├── 1-Getting Started With JavaScript.md
├── 10. switch statement.md
├── 11. while Loop.md
├── 12. for loop.md
├── 13. break and continue.md
├── 14. JavaScript Functions.md
├── 15. Arrow functions.md
├── 16. Global and local scope.md
├── 17. JavaScript Objects.md
├── 18. Strings.md
├── 19. 10 String Methods_Properties You Must know.md
├── 2. JavaScript Variables.md
├── 20. JavaScript Array.md
├── 21. Array Methods You Must Know.md
├── 22. map, filter, reduce.md
├── 23. for...in and for...of Loop.md
├── 24. Numbers.md
├── 3. JavaScript Take Input.md
├── 4. JavaScript Comments.md
├── 5. JavaScript Operators and Arithmetic operators.md
├── 6. Booleans and Boolean Expression.md
├── 7. Basic Type conversion.md
├── 8. if_else Statement.md
├── 9. Ternary Operator.md
└── readme


/1-Getting Started With JavaScript.md:
--------------------------------------------------------------------------------
 1 | # 1- Getting Started With JavaScript
 2 | ***
 3 | JavaScript is one of the most popular and dynamic programming languages out there.
 4 | ## Programs in the Videos
 5 | ```js
 6 | console.log("Hello, World");
 7 | ```
 8 | **Output**
 9 | 
10 | ```
11 | Hello, World
12 | ```
13 | The console.log() prints whatever object that is inside the parentheses `()`.
14 | 
15 | 


--------------------------------------------------------------------------------
/10. switch statement.md:
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  1 | # 10. switch Statement
  2 | ## Example
  3 | ```js
  4 | const number = parseInt(prompt('Enter a number between 1 to 7: '));
  5 | 
  6 | switch (number) {
  7 |     case 1:
  8 |         console.log("Sunday");
  9 |         break;
 10 |     case 2:
 11 |         console.log("Monday");
 12 |         break;
 13 |     case 3:
 14 |         console.log("Tuesday");
 15 |         break;
 16 |     case 4:
 17 |         console.log("Wednesday");
 18 |         break;
 19 |     case 5:
 20 |         console.log("Thursday");
 21 |         break;
 22 |     case 6:
 23 |         console.log("Friday");
 24 |         break;
 25 |     case 7:
 26 |         console.log("Saturday");
 27 |         break;
 28 |     default:
 29 |         console.log("Invalid Number");
 30 | }
 31 | ```
 32 | **Output**
 33 | ```
 34 | Enter a number between 1 to 7: 4
 35 | Wednesday
 36 | ```
 37 | ***
 38 | ## Omitting break
 39 | ```js
 40 | const number = parseInt(prompt('Enter a number between 1 to 7: '));
 41 | 
 42 | switch (number) {
 43 |     case 1:
 44 |         console.log("Sunday");
 45 |     case 2:
 46 |         console.log("Monday");
 47 |     case 3:
 48 |         console.log("Tuesday");
 49 |     case 4:
 50 |         console.log("Wednesday");
 51 |     case 5:
 52 |         console.log("Thursday");
 53 |     case 6:
 54 |         console.log("Friday");
 55 |     case 7:
 56 |         console.log("Saturday");
 57 |     default:
 58 |         console.log("Invalid Number");
 59 | }
 60 | ```
 61 | **Output**
 62 | ```
 63 | Wednesday
 64 | Thursday
 65 | Friday
 66 | Saturday
 67 | Invalid Number
 68 | ```
 69 | ***
 70 | ## JavaScript switch With Multiple Case
 71 | ```js
 72 | const day = prompt('Enter the day: ');
 73 | 
 74 | switch (day) {
 75 |     case 'Monday':
 76 |     case 'Tuesday':
 77 |     case 'Wednesday':
 78 |     case 'Thursday':;
 79 |     case 'Friday':
 80 |         console.log("Weekday");
 81 |         break;
 82 |     case 'Saturday':
 83 |     case 'Sunday':
 84 |         console.log("Weekend");
 85 |         break;
 86 |     default:
 87 |         console.log("Invalid Day");
 88 | }
 89 | ```
 90 | **Output**
 91 | ```
 92 | Weekday
 93 | ```
 94 | ## Simple Calculator
 95 | ```js
 96 | // take the operator input
 97 | const operator = prompt('Enter operator ( either +, -, * or / ): ');
 98 | 
 99 | // take the operand input
100 | const number1 = parseFloat(prompt('Enter first number: '));
101 | const number2 = parseFloat(prompt('Enter second number: '));
102 | 
103 | let result;
104 | switch(operator) {
105 |     case '+':
106 |         result = number1 + number2;
107 |         break;
108 |     case '-':
109 |         result = number1 - number2;
110 |         break;
111 |     case '*':
112 |         result = number1 * number2;
113 |         break;
114 |     case '/':
115 |         result = number1 / number2;
116 |         break;
117 | 
118 |     default:
119 |         console.log('Invalid operator');
120 |         break;
121 | }
122 | console.log(`${number1} ${operator} ${number2} = ${result}`);
123 | ```
124 | **Output**
125 | ```
126 | Enter operator: *
127 | Enter first number: 5
128 | Enter second number: 8.8
129 | 5 * 8.8 = 44
130 | ```
131 | ***
132 | ## Programming Task
133 | **Can you use switch statements to create a program that takes the number input from the user from 1 to 12. And, print the corresponding month based on the input value.**
134 | ### Solution:
135 | ```js
136 | const number = parseInt(prompt('Enter a number from 1 to 12: '));
137 | 
138 | let result;
139 | switch(number) {
140 |     case 1:
141 |         result = "January";
142 |         break;
143 |     case 2:
144 |         result = "Febraury";
145 |         break;
146 |     case 3:
147 |         result = "March";
148 |         break;
149 |     case 4:
150 |         result = "April";
151 |         break;
152 |     case 5:
153 |         result = "May";
154 |         break;
155 |     case 6:
156 |         result = "June";
157 |         break;
158 |     case 7:
159 |         result = "July";
160 |         break;
161 |     case 8:
162 |         result = "August";
163 |         break;
164 |     case 9:
165 |         result = "September";
166 |         break;
167 |     case 10:
168 |         result = "October";
169 |         break;
170 |     case 11:
171 |         result = "November";
172 |         break;
173 |     case 12:
174 |         result = "December";
175 |         break;
176 |     default:
177 |         console.log('Invalid number');
178 |         break;
179 | }
180 | console.log(result);
181 | ```
182 | **Output**
183 | ```
184 | Enter a number from 1 to 12: 3
185 | March
186 | ```
187 | ***
188 | ## Programiz Quiz 
189 | **Q. Which of the cases is executed in the following code?**
190 | ```js
191 | let value = 4;
192 | 
193 | switch(value) {
194 |   case 1:
195 |   case 2:
196 |   default:
197 | }
198 | ```
199 | 1. case 1
200 | 2. case 2
201 | 3. case 4
202 | 4. default
203 | 
204 | Answer: 4
205 | 


--------------------------------------------------------------------------------
/11. while Loop.md:
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  1 | # 11. while Loop
  2 | ## Infinite Loop Example
  3 | ```js
  4 | while (1 < 5) {
  5 |     console.log("Learning while loop.");
  6 |     console.log("JavaScript is fun.");
  7 | }
  8 | ```
  9 | **Output**
 10 | ```
 11 | Learning while loop.
 12 | JavaScript is fun.
 13 | Learning while loop.
 14 | JavaScript is fun.
 15 | Learning while loop.
 16 | JavaScript is fun.
 17 | Learning while loop.
 18 | JavaScript is fun.
 19 | Learning while loop.
 20 | JavaScript is fun.
 21 | ............
 22 | ```
 23 | ***
 24 | ## while Example 1
 25 | ```js
 26 | let count = 1;
 27 | while (count < 5) {
 28 |     console.log("Learning while loop.");
 29 |     console.log("JavaScript is fun.");
 30 |     count = count + 1;
 31 | }
 32 | ```
 33 | **Output**
 34 | ```
 35 | Learning while loop.
 36 | JavaScript is fun.
 37 | Learning while loop.
 38 | JavaScript is fun.
 39 | Learning while loop.
 40 | JavaScript is fun.
 41 | Learning while loop.
 42 | JavaScript is fun.
 43 | ```
 44 | ***
 45 | ## while loop Example 2
 46 | ```js
 47 | let count = 1;
 48 | while (count < 5) {
 49 |     console.log("Learning while loop.");
 50 |     console.log("JavaScript is fun.");
 51 |     console.log(count);
 52 |     count = count + 1;   
 53 | }
 54 | ```
 55 | **Output**
 56 | ```
 57 | Learning while loop.
 58 | JavaScript is fun.
 59 | 1
 60 | Learning while loop.
 61 | JavaScript is fun.
 62 | 2
 63 | Learning while loop.
 64 | JavaScript is fun.
 65 | 3
 66 | Learning while loop.
 67 | JavaScript is fun.
 68 | 4
 69 | ```
 70 | ## Creating Multiplication Table
 71 | ```js
 72 | const number = parseInt(prompt("Enter a number: "));
 73 | let count = 1;
 74 | while (count <= 10) {
 75 |     const product = number * count;
 76 |     console.log(product);
 77 |     count = count + 1;
 78 | }
 79 | ```
 80 | **Output**
 81 | ```
 82 | Enter a number: 9
 83 | 9
 84 | 18
 85 | 27
 86 | 36
 87 | 45
 88 | 54
 89 | 63
 90 | 72
 91 | 81
 92 | 90
 93 | ```
 94 | ***
 95 | ## Useful Output Message
 96 | ```js
 97 | const number = parseInt(prompt("Enter a number: "));
 98 | let count = 1;
 99 | while (count <= 10) {
100 |     const product = number * count;
101 |     console.log(`${number} * ${count} = ${product}`);
102 |     count = count + 1;
103 | }
104 | ```
105 | **Output**
106 | ```
107 | Enter a number: 9
108 | 9 * 1 = 9
109 | 9 * 2 = 18
110 | 9 * 3 = 27
111 | 9 * 4 = 36
112 | 9 * 5 = 45
113 | 9 * 6 = 54
114 | 9 * 7 = 63
115 | 9 * 8 = 72
116 | 9 * 9 = 81
117 | 9 * 10 = 90
118 | ```
119 | ***
120 | ## do While Loop
121 | ### Example 1
122 | ```js
123 | let count = 1;
124 | do {
125 |     console.log(count);
126 |     count = count + 1;
127 | } while (count < 5)
128 | ```
129 | **Output**
130 | ```
131 | 1
132 | 2
133 | 3
134 | 4
135 | ```
136 | ***
137 | 
138 | ## Programming Task
139 | **Can you use the while loop to print the multiplication table for the given number. But this time, you have to print the number from 10 to 1. So the output would be something like this.**
140 | ```js
141 | 9 * 10 = 90
142 | 9 * 9 = 81
143 | 9 * 8 = 72
144 | 9 * 7 = 63
145 | 9 * 6 = 54
146 | 9 * 5 = 45
147 | 9 * 4 = 36
148 | 9 * 3 = 27
149 | 9 * 2 = 18
150 | 9 * 1 = 9
151 | ```
152 | ### Solution:
153 | ```js
154 | const number = parseInt(prompt("Enter a number: "));
155 | let count = 10;
156 | while (count >= 1) {
157 |     const product = number * count;
158 |     console.log(`${number} * ${count} = ${product}`);
159 |     count = count - 1;
160 | }
161 | ```
162 | **Output**
163 | ```
164 | Enter a number: 9
165 | 9 * 10 = 90
166 | 9 * 9 = 81
167 | 9 * 8 = 72
168 | 9 * 7 = 63
169 | 9 * 6 = 54
170 | 9 * 5 = 45
171 | 9 * 4 = 36
172 | 9 * 3 = 27
173 | 9 * 2 = 18
174 | 9 * 1 = 9
175 | ```
176 | ***
177 | ## Programiz Quiz 
178 | **Q. Which of the following causes an infinite loop?**
179 | 
180 | 1. while (true) {...}
181 | 2. let i = 3;
182 | while (i < 4) {...}
183 | 3. let i = 3;
184 | do {
185 | ...} while(i < 4)
186 | 4. All of the above
187 | 
188 | Answer: 4
189 | 


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/12. for loop.md:
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  1 | # 12. for loop
  2 | ## for loop Example
  3 | ```js
  4 | for (let i = 1; i <= 5; i++) {
  5 |     console.log("Learning for loop.");
  6 |     console.log("JavaScript is fun.");
  7 | 
  8 |     console.log(i);
  9 | }
 10 | ```
 11 | **Output**
 12 | ```
 13 | Learning for loop.
 14 | JavaScript is fun.
 15 | 1
 16 | Learning for loop.
 17 | JavaScript is fun.
 18 | 2
 19 | Learning for loop.
 20 | JavaScript is fun.
 21 | 3
 22 | Learning for loop.
 23 | JavaScript is fun.
 24 | 4
 25 | Learning for loop.
 26 | JavaScript is fun.
 27 | 5
 28 | ```
 29 | ***
 30 | ## Creating Multiplication Table
 31 | ```js
 32 | const number = parseInt(prompt("Enter a number: "));
 33 | for (let count = 1; count <= 10; count++) {
 34 |     const product = number * count;
 35 |     console.log(`${number} * ${count} = ${product}`);
 36 | }
 37 | ```
 38 | **Output**
 39 | ```
 40 | Enter a number: 9
 41 | 9 * 1 = 9
 42 | 9 * 2 = 18
 43 | 9 * 3 = 27
 44 | 9 * 4 = 36
 45 | 9 * 5 = 45
 46 | 9 * 6 = 54
 47 | 9 * 7 = 63
 48 | 9 * 8 = 72
 49 | 9 * 9 = 81
 50 | 9 * 10 = 90
 51 | ```
 52 | ***
 53 | ## for...in Loop Example
 54 | ```js
 55 | const student = {
 56 |     name: 'Monica',
 57 |     class: 7,
 58 |     age: 12
 59 | }
 60 | 
 61 | for ( let data in student ) {
 62 |     console.log(`${data} => ${student[data]}`);
 63 | }
 64 | ```
 65 | **Output**
 66 | ```
 67 | name => Monica
 68 | class => 7
 69 | age => 12
 70 | ```
 71 | ***
 72 | ## for of loop
 73 | ```js
 74 | const students = ['John', 'Sara', 'Jack'];
 75 | for ( let data of students) {
 76 |     console.log(data);
 77 | }
 78 | ```
 79 | **Output**
 80 | ```
 81 | John
 82 | Sara
 83 | Jack
 84 | ```
 85 | ***
 86 | ### Get Character
 87 | ```js
 88 | let language = "JavaScript";
 89 | for (let character of language) {
 90 |     console.log(character);
 91 | }
 92 | ```
 93 | **Output**
 94 | ```
 95 | J
 96 | a
 97 | v
 98 | a
 99 | S
100 | c
101 | r
102 | i
103 | p
104 | t
105 | ```
106 | ## Programming Task
107 | **Can you use the for loop to print all the even numbers from 1 to 100. So the output would be something like this.**
108 | ```js
109 | 2
110 | 4
111 | 6
112 | 8
113 | 10
114 | 12
115 | ........
116 | ```
117 | ### Solution:
118 | ```js
119 | for (let i = 1; i <= 100; i++) {
120 |     if(i % 2 == 0) {
121 |         console.log(i);
122 |     }
123 | }
124 | ```
125 | **Output**
126 | ```
127 | 2
128 | 4
129 | 6
130 | 8
131 | 10
132 | 12
133 | 14
134 | 16
135 | 18
136 | 20
137 | 22
138 | 24
139 | 26
140 | 28
141 | 30
142 | 32
143 | 34
144 | 36
145 | 38
146 | 40
147 | 42
148 | 44
149 | 46
150 | 48
151 | 50
152 | 52
153 | 54
154 | 56
155 | 58
156 | 60
157 | 62
158 | 64
159 | 66
160 | 68
161 | 70
162 | 72
163 | 74
164 | 76
165 | 78
166 | 80
167 | 82
168 | 84
169 | 86
170 | 88
171 | 90
172 | 92
173 | 94
174 | 96
175 | 98
176 | 100
177 | ```
178 | ***
179 | ## Programiz Quiz 
180 | **Q. Which of the following loops is used to iterate over keys of an object?**
181 | 
182 | 1. for each loop
183 | 2. for...in loop
184 | 3. for of loop
185 | 4. for loop
186 | 
187 | 
188 | Answer: 2
189 | 


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/13. break and continue.md:
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  1 | # 13. break and continue
  2 | ## for loop without break Example
  3 | ```js
  4 | for (let i = 1; i <= 5; i++) {
  5 |     console.log(i);
  6 | }
  7 | ```
  8 | **Output**
  9 | ```
 10 | 1
 11 | 2
 12 | 3
 13 | 4
 14 | 5
 15 | ```
 16 | ***
 17 | ## for loop with break Example
 18 | ```js
 19 | for (let i = 1; i <= 5; i++) {
 20 |     console.log(i);
 21 |     break;
 22 | }
 23 | ```
 24 | **Output**
 25 | ```
 26 | 1
 27 | ```
 28 | ***
 29 | ## break with specific condition
 30 | ```js
 31 | for (let i = 1; i <= 5; i++) {
 32 |     if (i == 3) {
 33 |         break;
 34 |     }
 35 |     console.log(i);
 36 | }
 37 | ```
 38 | **Output**
 39 | ```
 40 | 1
 41 | 2
 42 | ```
 43 | ***
 44 | ## break with while
 45 | ```js
 46 | while (true) {
 47 |     let number = parseFloat(prompt("Enter a number: "));
 48 |     if (number < 0) {
 49 |         break;
 50 |     }
 51 |     console.log(number);
 52 | }
 53 | ```
 54 | **Output**
 55 | ```
 56 | Enter a number: 5
 57 | 5
 58 | Enter a number: 9
 59 | 9
 60 | Enter a number: -4
 61 | -4
 62 | ```
 63 | ***
 64 | ### continue Statement
 65 | ```js
 66 | for (let i = 1; i <= 5; i++) {
 67 |  
 68 |     if (i == 3) {
 69 |         continue;
 70 |     }
 71 | 
 72 |     console.log(i);
 73 | }
 74 | ```
 75 | **Output**
 76 | ```
 77 | 1
 78 | 2
 79 | 4
 80 | 5
 81 | ```
 82 | ## break and continue with while
 83 | ```js
 84 | while (true) {
 85 |     let number = parseFloat(prompt("Enter a number: "));
 86 |     if (number < 0) {
 87 |         break;
 88 |     }
 89 |     if (number % 2 != 0) {
 90 |       continue;
 91 |     }
 92 | 
 93 |     console.log(number);
 94 | }
 95 | ```
 96 | **Output**
 97 | ```
 98 | Enter a number: 4
 99 | 4
100 | Enter a number: 9
101 | Enter a number: 28
102 | 28
103 | Enter a number: -34
104 | ```
105 | ## Programming Task
106 | **Can you create a program that takes the input from the user. If the user enters a prime number, print the prime number. If the user enters a negative or non-prime number, ask the user for another number. And when the user enters a number greater than 100, terminate the loop.**
107 | ### Solution:
108 | ```js
109 | while (true) {
110 |     let number = parseFloat(prompt("Enter a number: "));
111 |     if(number > 100) {
112 |         break;
113 |     }
114 |     
115 |     let isPrime = true;
116 |     for (let i = 2; i < number; i++) {
117 |         if (number % i == 0) {
118 |             isPrime = false;
119 |             break;
120 |         }
121 |     }
122 |     
123 |     if (number < 0 || !isPrime) {
124 |         continue;
125 |     }
126 |     
127 |     else if (isPrime) {
128 |     	console.log(number);
129 |     }
130 | }
131 | ```
132 | **Output**
133 | ```
134 | Enter a number: 5
135 | Enter a number: 8
136 | Enter a number: 11
137 | Enter a number: 111
138 | 5
139 | 11
140 | ```
141 | ***
142 | ## Programiz Quiz 
143 | **Q. Which of the following keywords is used to terminate a loop?**
144 | 
145 | 1. terminate
146 | 2. break
147 | 3. continue
148 | 4. loop
149 | 
150 | Answer: 2
151 | 
152 | 


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/14. JavaScript Functions.md:
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  1 | # JavaScript Functions
  2 | ### Function Example 1
  3 | 
  4 | ```js
  5 | function greet() {
  6 |     console.log("Hello there");
  7 | }
  8 | greet();
  9 | ```
 10 | **Output**
 11 | ```
 12 | Hello there
 13 | ```
 14 | ***
 15 | ### Function Example 2
 16 | ```js
 17 | function greet() {
 18 |     console.log("Hello there");
 19 | }
 20 | greet();
 21 | console.log("After function call.");
 22 | ```
 23 | **Output**
 24 | ```
 25 | Hello there
 26 | After function call
 27 | ```
 28 | ***
 29 | ### Function Example 3
 30 | ```js
 31 | function greet() {
 32 |     console.log("Hello there");
 33 | }
 34 | greet();
 35 | greet();
 36 | greet();
 37 | ```
 38 | **Output**
 39 | ```
 40 | Hello there
 41 | Hello there
 42 | Hello there
 43 | ```
 44 | ***
 45 | ## Function arguments
 46 | ### Function Arguments Example 1
 47 | ```js
 48 | function greet(name) {
 49 |     console.log("Hello " + name);
 50 | }
 51 | 
 52 | greet();
 53 | ```
 54 | **Output**
 55 | ```
 56 | Hello undefined
 57 | ```
 58 | ***
 59 | ### Function Arguments Example 2
 60 | ```js
 61 | function greet(name) {
 62 |     console.log("Hello " + name);
 63 | }
 64 | 
 65 | greet("Jude");
 66 | ```
 67 | **Output**
 68 | ```
 69 | Hello Jude
 70 | ```
 71 | ***
 72 | ### Function Arguments Example 3
 73 | ```js
 74 | function greet(name) {
 75 |     console.log("Hello " + name);
 76 | }
 77 | 
 78 | greet("Jude");
 79 | greet("Jack");
 80 | ```
 81 | **Output**
 82 | ```
 83 | Hello Jude
 84 | Hello Jack
 85 | ```
 86 | ***
 87 | ## Passing Multiple Arguments
 88 | ```js
 89 | function addNumbers(n1, n2) {
 90 |     let result = n1 + n2;
 91 |     console.log("The sum is " + result);
 92 | }
 93 | 
 94 | let number1 = 6.6;
 95 | let number2 = 2.5;
 96 | addNumbers(number1, number2);
 97 | ```
 98 | **Output**
 99 | ```
100 | The sum is 9.1
101 | ```
102 | ***
103 | ## Return Value from a Function
104 | ```js
105 | function addNumbers(n1, n2) {
106 |     let result = n1 + n2;
107 |     return result;
108 | }
109 | 
110 | let sum = addNumbers(6.6, 2.5);
111 | console.log("The sum is " + sum);
112 | ```
113 | **Output**
114 | ```
115 | The sum is 9.1
116 | ```
117 | ## JavaScript Built-in Functions
118 | ```js
119 | const num = 9;
120 | const squareRoot = Math.sqrt(num);
121 | console.log(`The square root of ${num} is ${squareRoot}`);
122 | ```
123 | **Output**
124 | ```
125 | The square root of 9 is 3
126 | ```
127 | ***
128 | ## Programming Task
129 | **Can you create a program that can tell us if someone is eligible to vote? For this,
130 | Create a function canVote that accepts the age of the person.
131 | If the age is above 18, then return true else false
132 | Call the function for ages 17, 20 and 65 to verify if it is working correctly or not.**
133 | ### Solution:
134 | ```js
135 | function canVote(age) {
136 |     if (age > 18) {
137 |         return true;
138 |     } else {
139 |         return false;
140 |     }
141 | }
142 | 
143 | const result1 = canVote(17);
144 | console.log(result1);
145 | const result2 = canVote(20);
146 | console.log(result2);
147 | const result3 = canVote(65);
148 | console.log(result3);
149 | ```
150 | **Output**
151 | ```
152 | false
153 | true
154 | true
155 | ```
156 | ***
157 | ### Programiz Quiz
158 | **Q. What will be the output of the following code?**
159 | ```js
160 | console.log(sqrt(9));
161 | ```
162 | 1. 3
163 | 2. 81
164 | 3. error
165 | 4. None of the above
166 | 
167 | Answer: 1
168 | 
169 | 
170 | 
171 | 


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/15. Arrow functions.md:
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  1 | # JavaScript Arrow Functions
  2 | ### Example 1
  3 | ```js
  4 | function greet() {
  5 |     console.log("Good Morning");
  6 | }
  7 | 
  8 | greet();
  9 | ```
 10 | **Output**
 11 | ```
 12 | Good Morning
 13 | ```
 14 | ***
 15 | ### Example 2
 16 | ```js
 17 | const greet = () => console.log("Good Morning");
 18 | 
 19 | greet();
 20 | ```
 21 | **Output**
 22 | ```
 23 | Good Morning
 24 | ```
 25 | ***
 26 | ### Example 3
 27 | ```js
 28 | const greet = () => {
 29 |   console.log("Good Morning");
 30 |   console.log("How are you?");
 31 | }
 32 | 
 33 | greet();
 34 | ```
 35 | **Output**
 36 | ```
 37 | Good Morning
 38 | How are you?
 39 | ```
 40 | ***
 41 | ## Arrow function with Argument 
 42 | ### Example 1
 43 | ```js
 44 | let addNumbers = (a, b) => console.log(a + b);
 45 | 
 46 | addNumbers(5, 9);
 47 | ```
 48 | **Output**
 49 | ```
 50 | 14
 51 | ```
 52 | ***
 53 | ### Example 2
 54 | ```js
 55 | let addNumbers = a => console.log(a ** 2);
 56 | 
 57 | addNumbers(5, 9);
 58 | ```
 59 | **Output**
 60 | ```
 61 | 25
 62 | ```
 63 | ## Arrow Function with return statement
 64 | ```js
 65 | let addNumbers = (a, b) => {
 66 |     let result = a + b;
 67 |     return result;
 68 | }
 69 | let sum = addNumbers(5, 8);
 70 | console.log("The sum is " + sum);
 71 | ```
 72 | **Output**
 73 | ```
 74 | The sum is 13.
 75 | ```
 76 | ***
 77 | ```js
 78 | let addNumbers = (a, b) => {
 79 |     let result = a + b;
 80 |     return result;
 81 |     console.log("After Return");
 82 | }
 83 | let sum = addNumbers(5, 8);
 84 | console.log("The sum is " + sum);
 85 | ```
 86 | **Output**
 87 | ```
 88 | Result = 17
 89 | ```
 90 | ***
 91 | ## Programming Task
 92 | **Can you create a program using an arrow function to check if the number entered by the user is a prime number or not. This function should compute the result and return them to the function call. And, the results should be printed from outside the function.**
 93 | ### Solution:
 94 | ```js
 95 | let findPrime = (number) => {
 96 |     let result = true;
 97 |     for (let i = 2; i <= number -1; i++) {
 98 |         if(number % i == 0) {
 99 |             result = false;
100 |             break;
101 |         }
102 |     }
103 |     return result;
104 | }
105 | 
106 | const userValue = prompt(parseInt("Enter a positive number: "));
107 | let checkResult = findPrime(userValue);
108 | if(checkResult) {
109 |     console.log("The number is prime.");
110 | } else {
111 |     console.log("The number is not prime.");
112 | }
113 | ```
114 | **Output**
115 | ```
116 | Enter a positive number: 435
117 | The number is not prime.
118 | ```
119 | ***
120 | ## Programiz Quiz
121 | **Q.  What is the correct way to call this arrow function?**
122 |  ```js
123 | let calculatePrime = (number) => {...}
124 | ```
125 | 1. (5) =>
126 | 2. =>(5);
127 | 3. calculatePrime(5) =>
128 | 4. calculatePrime(5);
129 | 
130 | Answer: 4
131 | 
132 | 
133 | 


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/16. Global and local scope.md:
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  1 | ## Scope
  2 | ```js
  3 | let number = 5;
  4 | console.log(number);
  5 | ```
  6 | **Output**
  7 | ```
  8 | 5
  9 | ```
 10 | ***
 11 | ## Local Scope
 12 | ### Example 1
 13 | ```js
 14 | function addNumbers (n1, n2) {
 15 |     let result = n1 + n2;
 16 |     console.log(result);
 17 | }
 18 | 
 19 | addNumbers(4, 9);
 20 | ```
 21 | **Output**
 22 | ```
 23 | 13
 24 | ```
 25 | ***
 26 | ### Example 2
 27 | ```js
 28 | function addNumbers (n1, n2) {
 29 |     let result = n1 + n2;
 30 |     console.log(result);
 31 | }
 32 | 
 33 | addNumbers(4, 9);
 34 | console.log(result);
 35 | ```
 36 | **Output**
 37 | ```
 38 | ReferenceError: Can't find variable: result
 39 | ```
 40 | ***
 41 | ### Example 3
 42 | ```js
 43 | function addNumbers (n1, n2) {
 44 |     let result = n1 + n2;
 45 |     console.log(result);
 46 | }
 47 | 
 48 | addNumbers(4, 9);
 49 | 
 50 | let result = 123;
 51 | console.log(result);
 52 | ```
 53 | **Output**
 54 | ```
 55 | 13
 56 | 123
 57 | ```
 58 | ***
 59 | ## Global Scope
 60 | ### Example 1
 61 | ```js
 62 | let result;
 63 | 
 64 | function addNumbers (n1, n2) {
 65 |     result = n1 + n2;
 66 | }
 67 | 
 68 | addNumbers(4, 9);
 69 | console.log(result);
 70 | ```
 71 | **Output**
 72 | ```
 73 | 13
 74 | ```
 75 | ***
 76 | ### Change the value of Global Variable
 77 | ```js
 78 | let message = "hello";
 79 | 
 80 | function greet() {
 81 |     message = "How are you?"
 82 | 
 83 | }
 84 | 
 85 | // before the function call
 86 | console.log(message);
 87 | 
 88 | greet();
 89 | 
 90 | //after the function call
 91 | console.log(message);
 92 | ```
 93 | **Output**
 94 | ```
 95 | hello
 96 | How are you?
 97 | ```
 98 | ***
 99 | ## Block Scoped
100 | ### Example 1
101 | ```js
102 | const addNumbers = (n1, n2) => {
103 |     let result = n1 + n2;
104 |     console.log(result);
105 |     if (result > 10) {
106 |         let result1 = "Positive";
107 |         console.log(result1)
108 |     }
109 | }
110 | 
111 | addNumbers(4, 9);
112 | ```
113 | **Output**
114 | ```
115 | 13
116 | Positive
117 | ```
118 | ***
119 | ### Example 2
120 | ```js
121 | const addNumbers = (n1, n2) => {
122 |     let result = n1 + n2;
123 |     console.log(result);
124 |     if (result > 10) {
125 |         let result1 = "Positive";
126 |         console.log(result1)
127 |     }
128 |     console.log(result1);
129 | }
130 | 
131 | addNumbers(4, 9);
132 | ```
133 | **Output**
134 | ```
135 | 13
136 | Positive
137 | ReferenceError: Can't find variable: result1
138 | ```
139 | ***
140 | ### Programiz Quiz
141 | **Q.  What is the output of the program?**
142 | ```js
143 | let a = 88;
144 | function checkValue() {
145 |     let a = 77;
146 |     a = a - 57;
147 | }
148 | checkValue();
149 | console.log(a);
150 | ```
151 | 1. 88
152 | 2. 77
153 | 3. 20
154 | 4. 31
155 | 
156 | Answer: 1
157 | 


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/17. JavaScript Objects.md:
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  1 | # JavaScript Objects
  2 | 
  3 | ```js
  4 | const person = {
  5 |     name: "John",
  6 |     age: 20,
  7 | };
  8 | console.log(person);
  9 | ```
 10 | **Output**
 11 | ```
 12 | {name: "John", age: 20}
 13 | ```
 14 | 
 15 | ## To find Type
 16 | ```js
 17 | const person = { 
 18 |     name: "John",
 19 |     age: 20,
 20 | };
 21 | console.log(person);
 22 | console.log(typeof(person));
 23 | ```
 24 | **Output**
 25 | ```
 26 | {name: "John", age: 20}
 27 | object
 28 | ```
 29 | ## Accessing Object Properties
 30 | ### Using dot notation
 31 | ```js
 32 | const person = { 
 33 |     name: "John", 
 34 |     age: 20,
 35 | };
 36 | console.log(person.name);
 37 | console.log(person.age);
 38 | ```
 39 | **Output**
 40 | ```
 41 | John
 42 | 20
 43 | ```
 44 | ## Change the value of an object
 45 | ```js
 46 | const person = { 
 47 |     name: "John", 
 48 |     age: 20,
 49 |     student: true
 50 | };
 51 | console.log(person.name);
 52 | console.log(person.age);
 53 | 
 54 | person.age = 29;
 55 | console.log(person.age);
 56 | ```
 57 | **Output**
 58 | ```
 59 | John
 60 | 20
 61 | 29
 62 | ```
 63 | ### Using bracket notation
 64 | ```js
 65 | const person = { 
 66 |     name: "John", 
 67 |     age: 20,
 68 | };
 69 | console.log(person["name"]);
 70 | console.log(person["age"]);
 71 | ```
 72 | **Output**
 73 | ```
 74 | John
 75 | 20
 76 | ```
 77 | ## Object Methods
 78 | ```js
 79 | const person = {
 80 |     name: "John",
 81 |     age: 30,
 82 |     greet: function() { console.log('hello') }
 83 | }
 84 | person.greet();
 85 | ```
 86 | **Output**
 87 | ```
 88 | hello
 89 | ```
 90 | ***
 91 | ## Programming Task
 92 | **Can you create an object named student with keys name, rollNo, totalMarks. Give any values you prefer.
 93 | Also, create two functions: first function to print the information about the student and a second function to check if the student passed the exam or not. If the totalMarks is  less than 40, print 'You failed'. If the totalMarks is greater than or equal to 40, print 'You passed'.**
 94 | ### Solution:
 95 | ```js
 96 | const student = {
 97 |     name: 'Jack',
 98 |     rollNo: 12,
 99 |     total_marks : 40
100 | }
101 | 
102 | function studentInfo() {
103 |     console.log(student.name);
104 |     console.log(student.rollNo);
105 |     console.log(student.total_marks);
106 | }
107 | 
108 | function checkResult() {
109 |     if (student.total_marks < 40) {
110 |         console.log('You failed.')
111 |     } else {
112 |         console.log('You passed.')
113 |     }
114 | }
115 | 
116 | studentInfo();
117 | checkResult();
118 | ```
119 | 
120 | **Output**
121 | ```
122 | Jack
123 | 12
124 | 40
125 | You passed.
126 | ```
127 | ## Programiz Quiz
128 | **Q.  What is the correct way to call this access the object value name?**
129 | ```js
130 | const student = {
131 |     name: "Sarah",
132 |     class: 10
133 | }
134 | ```
135 | 1. student[name]
136 | 2. student.name
137 | 3. student.name()
138 | 4. student["name"]()
139 | 
140 | Answer: 2
141 | 


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/18. Strings.md:
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  1 | # Strings
  2 | ## Example 1
  3 | ```js
  4 | let text = "JavaScript is fun";
  5 | console.log(text);
  6 | console.log(typeof(text));
  7 | ```
  8 | **Output**
  9 | ```
 10 | JavaScript is fun
 11 | string
 12 | ```
 13 | ***
 14 | ## Example 2
 15 | ```js
 16 | let age = 25;
 17 | let text = `I am ${age} years old`;
 18 | console.log(text);
 19 | console.log(typeof(text));
 20 | ```
 21 | **Output**
 22 | ```
 23 | I am 25 years old
 24 | string
 25 | ```
 26 | ***
 27 | ## Access String Characters
 28 | ```js
 29 | let text = "Hello";
 30 | console.log(text[0]);
 31 | console.log(text[1]);
 32 | console.log(text[2]);
 33 | ```
 34 | **Output**
 35 | ```
 36 | H
 37 | e
 38 | l
 39 | ```
 40 | ***
 41 | ## JavaScript String Length
 42 | ```js
 43 | let text = "Hello";
 44 | console.log(text.length);
 45 | ```
 46 | **Output**
 47 | ```
 48 | 5
 49 | ```
 50 | ***
 51 | ## charAt() Method
 52 | ```js
 53 | let text = "Hello";
 54 | console.log(text.charAt(0));
 55 | console.log(text.charAt(1));
 56 | console.log(text.charAt(2));
 57 | ```
 58 | **Output**
 59 | ```
 60 | H
 61 | e
 62 | l
 63 | ```
 64 | ***
 65 | ## JavaScript String is Case-Sensitive
 66 | ```js
 67 | let str1 = "HELLO";
 68 | let str2 = "hello";
 69 | 
 70 | console.log(str1 === str2);
 71 | ```
 72 | **Output**
 73 | ```
 74 | false
 75 | ```
 76 | ***
 77 | ## JavaScript Multiline Strings
 78 | ```js
 79 | const message = "Hello everyone. \
 80 | Welcome to our JavaScript tutorial. \
 81 | In this tutorial, you will learn about \
 82 | JavaScript in a fun and easy way.";
 83 | 
 84 | console.log(message);
 85 | ```
 86 | **Output**
 87 | ```
 88 | Hello everyone. Welcome to our JavaScript tutorial. In this tutorial, you will learn about JavaScript in a fun and easy way.
 89 | ```
 90 | 
 91 | ***
 92 | ## Programming Task
 93 | **Create a JavaScript string and find the first and last character of the string using the charAt() method.
 94 | Also find the length of the string.**
 95 | ### Solution:
 96 | ```js
 97 | const message = "Hello everyone. \
 98 |     Welcome to our JavaScript tutorial. \
 99 |     In this tutorial, you will learn about \
100 |     JavaScript in a fun and easy way.";
101 | 
102 | // length of the string
103 | const totalLength = message.length;
104 | console.log(`Length: ${totalLength}`)
105 |     
106 | // first character
107 | console.log(message.charAt(0));
108 | 
109 | //last character
110 | console.log(message.charAt(totalLength-1));
111 | ```
112 | **Output**
113 | ```
114 | Length: 136
115 | H
116 | .
117 | ```
118 | ***
119 | ## Programiz Quiz
120 | **Q. What is the output of the program?**
121 | ```js
122 | let message = "JavaScript";
123 | let len = message.length;
124 | 
125 | console.log(message.charAt(len - 2));
126 | ```
127 | 1. Error
128 | 2. p
129 | 3. t
130 | 4. J
131 | 
132 | Answer: 2
133 | 


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/19. 10 String Methods_Properties You Must know.md:
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  1 | # 19. 10 String Methods/Properties You Must know
  2 | ## 1. toUpperCase()
  3 | ```js
  4 | const text = "I like javascript";
  5 | const result = text.toUpperCase();
  6 | 
  7 | console.log(result);
  8 | ```
  9 | **Output**
 10 | ```
 11 | I LIKE JAVASCRIPT
 12 | ```
 13 | ***
 14 | ## 2. toLowerCase() Method
 15 | ```js
 16 | const text = "I LIKE JAVASCRIPT";
 17 | const result = text.toLowerCase();
 18 | 
 19 | console.log(result);
 20 | ```
 21 | **Output**
 22 | ```
 23 | i like javascript
 24 | ```
 25 | ***
 26 | ## 3. concat()
 27 | ```js
 28 | const text1 = "JavaScript";
 29 | const text2 = "Programming";
 30 | 
 31 | const result = text1.concat(text2);
 32 | console.log(result);
 33 | ```
 34 | **Output**
 35 | ```
 36 | JavaScriptProgramming
 37 | ```
 38 | ***
 39 | ## 4. replace()
 40 | ```js
 41 | const text = "Hello. My name is Punit."
 42 | console.log(text);
 43 | 
 44 | const result = text.replace("Hello", "Hi");
 45 | console.log(result);
 46 | ```
 47 | **Output**
 48 | ```
 49 | Hi. My name is Punit.
 50 | ```
 51 | ***
 52 | ## 5. split()
 53 | ```js
 54 | const text = "hello";
 55 | const result = text.split('');
 56 | console.log(result);
 57 | ```
 58 | **Output**
 59 | ```
 60 | ["h", "e", "l", "l", "o"]
 61 | ```
 62 | ***
 63 | ## 6. slice()
 64 | ```js
 65 | const text = "JavaScript";
 66 | const result = text.slice(0,4);
 67 | console.log(result);
 68 | ```
 69 | **Output**
 70 | ```
 71 | Java
 72 | ```
 73 | ***
 74 | ## 7. trim()
 75 | ```js
 76 | const text = "    JavaScript   ";
 77 | const result = text.trim();
 78 | console.log(result);
 79 | ```
 80 | **Output**
 81 | ```
 82 | JavaScript
 83 | ```
 84 | ***
 85 | ## 8. search()
 86 | ### Example 1
 87 | ```js
 88 | const text = "JavaScript is fun.";
 89 | const result = text.search("fun");
 90 | console.log(result);
 91 | ```
 92 | **Output**
 93 | ```
 94 | 14
 95 | ```
 96 | ***
 97 | ### Example 2
 98 | ```js
 99 | const text = "JavaScript is fun.";
100 | const result = text.search("funny");
101 | console.log(result);
102 | ```
103 | **Output**
104 | ```
105 | -1
106 | ```
107 | ***
108 | ## Programming Task
109 | **Create a string "I love Java". Convert the string to lowercase and check if the string consists of the substring "java". If yes, replace the substring "java" with "JavaScript".**
110 | ### Solution:
111 | ```js
112 | const text = "I love Java.";
113 | 
114 | const smallcase = text.toLowerCase();
115 | 
116 | const checkValue = smallcase.includes('java');
117 | 
118 | if(checkValue) {
119 |     const result = smallcase.replace('java', 'JavaScript');
120 |     console.log(result);
121 | }
122 | ```
123 | **Output**
124 | ```
125 | i love JavaScript.
126 | ```
127 | ***
128 | ## Programiz Quiz
129 | **Q. What is the output of the program?**
130 | ```js
131 | const message = "JavaScript is fun";
132 | const result = message.split(' ');
133 | 
134 | const value = result[0].charAt(2);
135 | console.log(value);
136 | ```
137 | 
138 | 1. s
139 | 2. v
140 | 3. is
141 | 4. fun
142 | 
143 | Answer: 2
144 | 
145 | 


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/2. JavaScript Variables.md:
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  1 | # 2. JavaScript Variables
  2 | ***
  3 | JavaScript is one of the most popular and dynamic programming languages out there.
  4 | ## Programs in the Videos
  5 | 
  6 | ## Strings
  7 | ```js
  8 | console.log("I love JavaScript");
  9 | console.log('JavaScript is fun');
 10 | ```
 11 | **Output**
 12 | 
 13 | ```
 14 | I love JavaScript
 15 | JavaScript is fun
 16 | ```
 17 | ```js
 18 | console.log(`I love JavaScript`);
 19 | console.log(`JavaScript is fun`);
 20 | ```
 21 | **Output**
 22 | 
 23 | ```
 24 | I love JavaScript
 25 | JavaScript is fun
 26 | ```
 27 | ## Numbers
 28 | ```js
 29 | console.log(8);
 30 | console.log(80.5);
 31 | ```
 32 | **Output**
 33 | 
 34 | ```
 35 | 8
 36 | 80.5
 37 | 
 38 | ```
 39 | ## JavaScript Variables
 40 | ```js
 41 | let language = "JavaScript";
 42 | console.log(language);
 43 | ```
 44 | **Output**
 45 | 
 46 | ```
 47 | JavaScript
 48 | ```
 49 | ***
 50 | ```js
 51 | let number = 5;
 52 | console.log(number);
 53 | ```
 54 | **Output**
 55 | 
 56 | ```
 57 | 5
 58 | ```
 59 | ***
 60 | ```js
 61 | var name = "Jack";
 62 | console.log(name);
 63 | ```
 64 | **Output**
 65 | 
 66 | ```
 67 | Jack
 68 | ```
 69 | ***
 70 | ```js
 71 | let name = "Punit"
 72 | console.log(name)
 73 | name = "James"
 74 | console.log(name)
 75 | ```
 76 | **Output**
 77 | ```
 78 | Punit
 79 | James
 80 | ```
 81 | ## Variable Using const
 82 | ```js
 83 | const passportNumber = 39983;
 84 | console.log(passportNumber);
 85 | ```
 86 | **Output**
 87 | ```
 88 | 39983
 89 | ```
 90 | ## Changing Value in const
 91 | ```js
 92 | const passportNumber = 39983;
 93 | console.log(passportNumber);
 94 | 
 95 | passportNumber = 44325;
 96 | console.log(passportNumber);
 97 | ```
 98 | **Output**
 99 | ```
100 | TypeError: Assignment to constant variable.
101 | ```
102 | ## JavaScript undefined
103 | ```js
104 | let name;
105 | console.log(name);
106 | ```
107 | **Output**
108 | ```
109 | undefined
110 | ```
111 | ***
112 | ```js
113 | let name = "Punit";
114 | console.log(name);
115 | 
116 | name = undefined;
117 | console.log(name);
118 | ```
119 | **Output**
120 | ```
121 | Punit
122 | undefined
123 | ```
124 | ***
125 | ## Print variables and string in single line
126 | ```js
127 | let city = "New York";
128 | console.log("City: " + city);
129 | ```
130 | **Output**
131 | ```
132 | City: New York
133 | ```
134 | ## Template Literal
135 | ```js
136 | let city = "New York";
137 | console.log(`City: ${city}`);
138 | ```
139 | **Output**
140 | ```
141 | City: New York
142 | ```
143 | ***
144 | ```js
145 | let city = "New York";
146 | let kfcLocation = 10;
147 | console.log("City: " + city +  ", " + "KFC Locations :" + kfcLocation);
148 | ```
149 | **Output**
150 | ```
151 | City: New York, KFC Locations :10
152 | ```
153 | ## Another Example
154 | ```js
155 | let city = "New York";
156 | let kfcLocation = 10;
157 | 
158 | console.log(`City: ${city}, KFC Locations: ${kfcLocation}`);
159 | ```
160 | **Output**
161 | ```
162 | City: New York, KFC Locations :10
163 | ```
164 | ***
165 | ## Programmiz Quiz
166 | **Q. Which of the following is the correct variable name?**
167 | 
168 | 1. switchNumber
169 | 2. 1switchNumber
170 | 3. switch number
171 | 4. switch
172 | 
173 | Answer: 1
174 | 
175 | 


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/20. JavaScript Array.md:
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  1 | # JavaScript Array
  2 | 
  3 | ```js
  4 | const name1 = "Jack";
  5 | const name2 = "Sarah";
  6 | const name3 = "Philip";
  7 | ...
  8 | ...
  9 | ...
 10 | const name100 = "Amy";
 11 | ```
 12 | ***
 13 | ## Create an Array
 14 | ```js
 15 | const routine = ['eat', 'sleep'];
 16 | console.log(routine);
 17 | ```
 18 | **Output**
 19 | ```
 20 |  [ 'eat', 'sleep' ]
 21 | ```
 22 | ***
 23 | 
 24 | ```js
 25 | const numbers = [2, 3, 5, 7];
 26 | console.log(numbers);
 27 | ```
 28 | **Output**
 29 | ```
 30 | [ 2, 3, 5, 7 ]
 31 | ```
 32 | ***
 33 | ```js
 34 | const arr = ['eat', 'sleep', 3, 5, 'run'];
 35 | console.log(arr);
 36 | ```
 37 | **Output**
 38 | ```
 39 | [ 'eat', 'sleep', 3, 5, 'run' ]
 40 | ```
 41 | ## Access Elements of an Array
 42 | ```js
 43 | const myArray = ['h', 'e', 'l', 'l', 'o'];
 44 | console.log(myArray[0]);
 45 | ```
 46 | **Output**
 47 | ```
 48 | h
 49 | ```
 50 | ***
 51 | 
 52 | ```js
 53 | const myArray = ['h', 'e', 'l', 'l', 'o'];
 54 | console.log(myArray[0]);
 55 | console.log(myArray[1]);
 56 | console.log(myArray[2]);
 57 | ```
 58 | **Output**
 59 | ```
 60 | h
 61 | e
 62 | l
 63 | ```
 64 | ***
 65 | ## Array length
 66 | ```js
 67 | const routine = [ 'eat', 'sleep'];
 68 | console.log(routine.length);
 69 | ```
 70 | **Output**
 71 | ```
 72 | 2
 73 | ```
 74 | ***
 75 | ## Add an Element to an Array
 76 | ```js
 77 | let routine = ['eat', 'sleep'];
 78 | 
 79 | // add an element at the end
 80 | routine.push('exercise');
 81 | console.log(routine);
 82 | ```
 83 | **Output**
 84 | ```
 85 | ['eat', 'sleep', 'exercise']
 86 | ```
 87 | ***
 88 | ## Change the Elements of an Array
 89 | ```js
 90 | let routine = ['eat', 'sleep'];
 91 | 
 92 | routine[1] = 'exercise';
 93 | console.log(routine);
 94 | ```
 95 | **Output**
 96 | ```
 97 | [ 'eat', 'exercise' ]
 98 | ```
 99 | ***
100 | ## Remove an Element from an Array
101 | ```js
102 | let routine = ['work', 'eat', 'sleep', 'exercise'];
103 | 
104 | // remove the last element
105 | routine.pop();
106 | console.log(routine);
107 | ```
108 | **Output**
109 | ```
110 | ['work', 'eat', 'sleep']
111 | ```
112 | ***
113 | ## Programming Task
114 | **Create an array named greet with values 'hello', 'hi'.
115 | Find the length of an array.
116 | Add the new element 'welcome' to the array.
117 | Find the new length of an array.**
118 | ### Solution:
119 | ```js
120 | const greet = ['hello', 'hi'];
121 | const greetLength = greet.length;
122 | console.log(greetLength);
123 | greet.push('welcome');
124 | const addGreetLength = greet.length;
125 | console.log(addGreetLength);
126 | ```
127 | **Output**
128 | ```
129 | 2
130 | 3
131 | ```
132 | ***
133 | ## Programiz Quiz
134 | **Q. What is the output of the program?**
135 | ```js
136 | let routine = [ 'eat', 'sleep'];
137 | routine.push('exercise');
138 | routine[4] = 'work';
139 | console.log(routine[3]);
140 | ```
141 | 1. Error
142 | 2. exercise
143 | 3. undefined
144 | 4. work
145 | 
146 | Answer: 3
147 | 
148 | 
149 | 
150 | 
151 | 
152 | 
153 | 
154 |    
155 | 


--------------------------------------------------------------------------------
/21. Array Methods You Must Know.md:
--------------------------------------------------------------------------------
  1 | # 8 Array Methods You Must Know 
  2 | ## 1. push() and unshift() Method
  3 | ```js
  4 | const fruits = ['apple', 'orange', 'mango'];
  5 | 
  6 | // add element at the end of array
  7 | fruits.push('pineapple');
  8 | console.log(fruits);
  9 | ```
 10 | ***
 11 | **Output**
 12 | ```
 13 | ["apple", "orange", "mango", "pineapple"]
 14 | ```
 15 | ***
 16 | ```js
 17 | const fruits = ['apple', 'orange', 'mango'];
 18 | 
 19 | // add element at the end of array
 20 | fruits.unshift('kiwi');
 21 | console.log(fruits);
 22 | ```
 23 | **Output**
 24 | ```
 25 | ["kiwi", "apple", "orange", "mango"]
 26 | ```
 27 | ***
 28 | ## 2. pop() and shift() Method
 29 | ```js
 30 | const fruits = ['apple', 'orange', 'mango'];
 31 | fruits.pop();
 32 | console.log(fruits);
 33 | ```
 34 | **Output**
 35 | ```
 36 | ["apple", "orange"]
 37 | ```
 38 | ***
 39 | ```js
 40 | const fruits = ['apple', 'orange', 'mango'];
 41 | 
 42 | fruits.shift();
 43 | console.log(fruits);
 44 | ```
 45 | **Output**
 46 | ```
 47 | ["orange", "mango"]
 48 | ```
 49 | ## 3. concat() Method
 50 | ```js
 51 | const array1 = ['hello', 'world'];
 52 | const array2 = ['JavaScript', 'programming'];
 53 | 
 54 | const result = array1.concat(array2);
 55 | console.log(result);
 56 | ```
 57 | **Output**
 58 | ```
 59 | [ 'hello', 'world', 'JavaScript', 'programming' ]
 60 | ```
 61 | ***
 62 | ## 4. sort() Method
 63 | ```js
 64 | const fruits = [apple, mango, papaya, 'kiwi'];
 65 | 
 66 | fruits.sort();
 67 | console.log(fruits);
 68 | ```
 69 | **Output**
 70 | ```
 71 | ["apple", "kiwi", "mango", "papaya"]
 72 | ```
 73 | ***
 74 | ## 5. slice() Method
 75 | ```js
 76 | const arrayValue = ['hello', 'world', 'JavaScript', 'programming'];
 77 | 
 78 | const result = arrayValue.slice(0, 3);
 79 | console.log(result);
 80 | ```
 81 | **Output**
 82 | ```
 83 | [ 'hello', 'world', 'JavaScript' ]
 84 | ```
 85 | ***
 86 | ```js
 87 | const arrayValue = ['hello', 'world', 'JavaScript', 'programming'];
 88 | 
 89 | const result = arrayValue.slice(2, 4);
 90 | console.log(result);
 91 | ```
 92 | **Output**
 93 | ```
 94 | [ 'JavaScript', 'programming' ]
 95 | ```
 96 | ***
 97 | ## 6. splice() Method
 98 | ```js
 99 | const arrayValue = ['hello', 'world', 'JavaScript', 'programming'];
100 | 
101 | arrayValue.splice(0, 2, 'language');
102 | console.log(arrayValue);
103 | ```
104 | **Output**
105 | ```
106 | [ 'language', 'JavaScript', 'programming' ]
107 | ```
108 | ***
109 | ## 7. includes() Method
110 | ```js
111 | const arrayValue = ['hello', 'world', 'JavaScript', 'programming'];
112 | 
113 | const result = arrayValue.includes('JavaScript');
114 | console.log(result);
115 | ```
116 | **Output**
117 | ```
118 | true
119 | ```
120 | ***
121 | ```js
122 | const arrayValue = ['hello', 'world', 'JavaScript', 'programming'];
123 | 
124 | const result = arrayValue.includes('Python');
125 | console.log(result);
126 | ```
127 | **Output**
128 | ```
129 | false
130 | ```
131 | ## 8. find() Method
132 | ```js
133 | const numbers = [2, 4, 7, 9, 12];
134 | const result = numbers.find(element => element > 5);
135 | console.log(result);
136 | ```
137 | **Output**
138 | ```
139 | 7
140 | ```
141 | ## Programming Task
142 | **Create an array value like this:
143 | ['I', 'Love', 'JavaScript'];
144 | Add the new value 'Programming' to the end of the array.
145 | Check if the array contains the text JavaScript. And if it does, print the text 'You are doing great. Keep learning.'**
146 | ### Solution:
147 | ```js
148 | const arrValue = ['I', 'Love', 'JavaScript'];
149 | arrValue.push('Programming');
150 | const result = arrValue.includes('JavaScript');
151 | if(result) {
152 |     console.log('You are doing great. Keep learning.');
153 | }
154 | ```
155 | **Output**
156 | ```
157 | You are doing great. Keep learning.
158 | ```
159 | ***
160 | ## Programiz quiz
161 | **Q. What is the output of the program? You can see the options there.**
162 | ```js
163 | const message = ['JavaScript', 'is', 'really', 'fun'];
164 | message.sort();
165 | const result = message.slice(0, 1);
166 | console.log(result);
167 | ```
168 | 1. ['JavaScript']
169 | 2. ['is']
170 | 3. ['fun']
171 | 4. ['really']
172 | 
173 | Answer: 1
174 | 
175 | 
176 | 
177 | 
178 | 
179 | 
180 | 
181 | 
182 | 
183 |    
184 | 


--------------------------------------------------------------------------------
/22. map, filter, reduce.md:
--------------------------------------------------------------------------------
  1 | # JavaScript Array
  2 | ```js
  3 | const number = [1, 2, 3, 4, 5];
  4 | ```
  5 | ## map() Method
  6 | ```js
  7 | const numbers = [1, 2, 3, 4, 5];
  8 | 
  9 | const square = numbers.map(item => item * item);
 10 | console.log(square);
 11 | ```
 12 | **Output**
 13 | ```
 14 | [ 1, 4, 9, 16, 25 ]
 15 | ```
 16 | ***
 17 | ```js
 18 | const names = ["James", "Marie", "Rosa"];
 19 | 
 20 | const fullNames = names.map(item => item + " Smith");
 21 | console.log(fullNames);
 22 | ```
 23 | **Output**
 24 | ```
 25 | [ 'James Smith', 'Marie Smith', 'Rosa Smith' ]
 26 | ```
 27 | ## filter() Method
 28 | ```js
 29 | const number = [1, 2, 3, 4, 5];
 30 | 
 31 | const result = number.filter(item => item < 3);
 32 | console.log(result);
 33 | ```
 34 | **Output**
 35 | ```
 36 | [1, 2]
 37 | ```
 38 | ***
 39 | ```js
 40 | const number = [1, 2, 3, 4, 5];
 41 | 
 42 | const result = number.filter(item => item % 2 !== 0);
 43 | console.log(result);
 44 | ```
 45 | **Output**
 46 | ```
 47 | [1, 3, 5, 7]
 48 | ```
 49 | ***
 50 | ## reduce() Method
 51 | ```js
 52 | const numbers = [1, 2, 3, 4, 5];
 53 | 
 54 | const reducer = (previousValue, currentValue) => previousValue + currentValue;
 55 | 
 56 | const result = numbers.reduce(reducer);
 57 | console.log(result);
 58 | ```
 59 | **Output**
 60 | ```
 61 | 15
 62 | ```
 63 | ***
 64 | ## Programming Task
 65 | **Create an array named greet with values 'hello', 'hi' and 'welcome'.
 66 | const greet = ['hello', 'hi', 'welcome'];
 67 | Use map() method to add a new string 'world' to each element of the array.
 68 | Remember two words should be separated by a space.
 69 | From the new array filter out the element that has more than 6 characters.**
 70 | ### Solution:
 71 | ```js
 72 | const greet = ['hello', 'hi', 'welcome'];
 73 | const newValue = greet.map(item => item + ' world');
 74 | console.log(newValue);
 75 | const finalValue = newValue.filter(item => item.length > 6);
 76 | console.log(finalValue);
 77 | ```
 78 | **Output**
 79 | ```
 80 | ["hello world", "hi world", "welcome world"]
 81 | ["hello world", "hi world", "welcome world"]
 82 | ```
 83 | ***
 84 | ## Programiz Quiz
 85 | **Q. What is the output of the program?**
 86 | ```js
 87 | const numbers = [53, 22, 0, 10, 15];
 88 | 
 89 | const reducer = (previousValue, currentValue) => previousValue - currentValue;
 90 | let result = array.reduce(reducer);
 91 | console.log(result);
 92 | ```
 93 | 1. Error
 94 | 2. 0
 95 | 3. 6
 96 | 4. 10
 97 | 
 98 | Answer: 3
 99 | 
100 | 
101 | 
102 | 
103 | 
104 | 
105 | 
106 | 
107 | 
108 | 
109 | 
110 |    
111 | 


--------------------------------------------------------------------------------
/23. for...in and for...of Loop.md:
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  1 | # for...in and for...of Loop
  2 | ## JavaScript for...of loop
  3 | **Example 1**
  4 | ```js
  5 | const numbers = [1, 3, 5, 9];
  6 | 
  7 | for (const element of numbers) {
  8 |   console.log(element);
  9 | }
 10 | ```
 11 | **Output**
 12 | ```
 13 | 1
 14 | 3
 15 | 5
 16 | 9
 17 | ```
 18 | ***
 19 | **Example 2**
 20 | ```js
 21 | const members = ['John', 'Sara', 'Jack'];
 22 |  
 23 | for (const name of members) {
 24 |   let fullname = name + ' ' + 'Smith';
 25 |   console.log(fullname);
 26 | }
 27 | ```
 28 | **Output**
 29 | ```
 30 | John Smith
 31 | Sara Smith
 32 | Jack Smith
 33 | ```
 34 | ## for...of with strings
 35 | ```js
 36 | const name = 'Programiz';
 37 | 
 38 | for (let i of name) {
 39 |     console.log(i);
 40 | }
 41 | ```
 42 | **Output**
 43 | ```
 44 | P
 45 | r
 46 | o
 47 | g
 48 | r
 49 | a
 50 | m
 51 | i
 52 | z
 53 | ```
 54 | ***
 55 | ## JavaScript for...in loop
 56 | **Example 1**
 57 | ```js
 58 | const student = {
 59 |     name: 'Monica',
 60 |     class: 7,
 61 |     age: 12
 62 | };
 63 | 
 64 | console.log(student);
 65 | ```
 66 | **Output**
 67 | ```
 68 | { name: 'Monica', class: 7, age: 12 }
 69 | ```
 70 | ***
 71 | **Example 2**
 72 | ```js
 73 | const student = {
 74 |     name: 'Monica',
 75 |     class: 7,
 76 |     age: 12
 77 | }
 78 | 
 79 | for (let key in student) {
 80 |   console.log(key);
 81 | }
 82 | ```
 83 | **Output**
 84 | ```
 85 | name
 86 | class
 87 | age
 88 | ```
 89 | **Example 3**
 90 | ```js
 91 | const student = {
 92 |     name: 'Monica',
 93 |     class: 7,
 94 |     age: 12
 95 | }
 96 | 
 97 | for (let key in student) {
 98 |   let value = student[key];
 99 |   console.log(`${key} => ${value}`);
100 | }
101 | ```
102 | **Output**
103 | ```
104 | name => Monica
105 | class => 7
106 | age => 12
107 | ```
108 | ## Change Object values using for...in
109 | ```js
110 | const employee = {
111 |     Jack: 24000,
112 |     Paul: 34000,
113 |     Monica: 32000
114 | }
115 | 
116 | for (let i in employee) {
117 |   let salary = employee[i] + 5000;
118 |   console.log(`${i} : ${salary}`);
119 | }
120 | ```
121 | **Output**
122 | ```
123 | Jack : 29000
124 | Paul : 39000
125 | Monica : 37000
126 | ```
127 | ## Programming Task
128 | **Create an array named names with values: "jack", "rosie", "mira".
129 | Now, use a for...of loop to print each name of the array.
130 | However, while printing the name, change the first character to uppercase.**
131 | ### Solution:
132 | ```js
133 | const names = ['jack', 'rosie', 'mira'];
134 | for (let element of names) {
135 |     const result = element.charAt(0).toUpperCase() + element.slice(1);
136 |     console.log(result);
137 | }
138 | ```
139 | **Output**
140 | ```
141 | "Jack"
142 | "Rosie"
143 | "Mira"
144 | ```
145 | ***
146 | ## Programiz Quiz
147 | **Q. What is the output of the program?**
148 | ```js
149 | const student = {
150 |     name: 'Monica',
151 |     class: 7,
152 |     age: 12
153 | }
154 | 
155 | for ( let key of student ) {
156 |     console.log(`${key} => ${student[key]}`);
157 | }
158 | ```
159 | 1. Error
160 | 2. name => Monica
161 | class => 7
162 | age => 12
163 | 3. name => name
164 | class => class
165 | age => age
166 | 4. Monica => Monica
167 | 7 => 7
168 | 12 => 12
169 | 
170 | Answer: 3
171 | 
172 | 


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/24. Numbers.md:
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  1 | # Numbers
  2 | ```js
  3 | const a = 3;
  4 | const b = 3.13;
  5 | 
  6 | console.log(typeof(a));
  7 | console.log(typeof(b));
  8 | ```
  9 | **Output**
 10 | ```
 11 | number
 12 | number
 13 | ```
 14 | ***
 15 | ## JavaScript Number() Function
 16 | ```js
 17 | const str = '23';
 18 | console.log(typeof(str));
 19 | 
 20 | const num = Number(str);
 21 | console.log(typeof(num));
 22 | ```
 23 | **Output**
 24 | ```
 25 | string
 26 | number
 27 | ```
 28 | ***
 29 | ```js
 30 | const bool = true;
 31 | const result = Number(bool);
 32 | console.log(result);
 33 | ```
 34 | **Output**
 35 | ```
 36 | 1
 37 | ```
 38 | ***
 39 | ## JavaScript NaN
 40 | ```js
 41 | const str = 'hello';
 42 | const result = Number(str);
 43 | console.log(result);
 44 | ```
 45 | **Output**
 46 | ```
 47 | NaN
 48 | ```
 49 | ***
 50 | ```js
 51 | const result = 4 - 'hello';
 52 | console.log(result);
 53 | ```
 54 | **Output**
 55 | ```
 56 | NaN
 57 | ```
 58 | ***
 59 | ```js
 60 | const result = isNaN((9);
 61 | console.log(result);
 62 | ```
 63 | **Output**
 64 | ```
 65 | false
 66 | ```
 67 | ***
 68 | ```js
 69 | const result = isNaN('hello');
 70 | console.log(result);
 71 | ```
 72 | **Output**
 73 | ```
 74 | true
 75 | ```
 76 | ***
 77 | ## JavaScript Number Methods
 78 | ### 1. isInteger() Method
 79 | ```js
 80 | const num = 32;
 81 | 
 82 | const result = Number.isInteger(num);
 83 | console.log(result);
 84 | ```
 85 | **Output**
 86 | ```
 87 | true
 88 | ```
 89 | ***
 90 | ```js
 91 | const num = 32.56;
 92 | 
 93 | const result = Number.isInteger(num);
 94 | console.log(result);
 95 | ```
 96 | **Output**
 97 | ```
 98 | false
 99 | ```
100 | ***
101 | ### 2. parseInt() and parseFloat() Method
102 | ```js
103 | const num = '5';
104 | const result = Number.parseInt(num);
105 | console.log(result);
106 | console.log(Number.isInteger(result));
107 | ```
108 | **Output**
109 | ```
110 | 5
111 | true
112 | ```
113 | ***
114 | ```js
115 | const num = 5.234234324324;
116 | const result = Number.parseInt(num);
117 | console.log(result);
118 | console.log(Number.isInteger(result));
119 | ```
120 | **Output**
121 | ```
122 | 5
123 | true
124 | ```
125 | ***
126 | ### 3. parseFloat() Method
127 | ```js
128 | const num = '5.23423423';
129 | 
130 | const result = Number.parseFloat(num);
131 | console.log(result);
132 | console.log(typeof(result));
133 | ```
134 | **Output**
135 | ```
136 | 5.23423423
137 | number
138 | ```
139 | ***
140 | ### 3. toFixed() Method
141 | ```js
142 | const num = 5.234234324324;
143 | const result = num.toFixed(2);
144 | console.log(result);
145 | ```
146 | **Output**
147 | ```
148 | 5.23
149 | ```
150 | ***
151 | ## Programming Task
152 | **Take numeric string input from the user.
153 | Convert that input into numbers.
154 | If the input has been converted to numbers, multiply that number by 10 and display the output.
155 | Else it is not converted to numbers, display "The input is not a numeric string."**
156 | ### Solution:
157 | ```js
158 | const numberInput = prompt("Enter a number: ");
159 | const result = Number(numberInput);
160 | if(typeof(result) == "number") {
161 |     console.log(result * 10);
162 | } else {
163 |     console.log("The input is not a numeric string.");
164 | }
165 | ```
166 | **Output**
167 | ```
168 | Enter a number: 5.5
169 | 55
170 | ```
171 | ***
172 | ## Programiz Quiz
173 | **Q. What is the output of the program?**
174 | ```js
175 | const num = '23' - '55';
176 | console.log(num);
177 | ```
178 | 1. Error
179 | 2. NaN
180 | 3. 32
181 | 4. -32
182 | 
183 | Answer: 4
184 | 


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/3. JavaScript Take Input.md:
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 1 | # 3. JavaScript Take Input
 2 | 
 3 | ## Take Input in JavaScript
 4 | ```js
 5 | const name = prompt("Enter your name:");
 6 | console.log(`Name: ${name}`);
 7 | ```
 8 | 
 9 | **Output**
10 | ```
11 | Enter your name: Punit
12 | Name: Punit
13 | ```
14 | ## JavaScript number input
15 | ```js
16 | const age = prompt("Enter your age:");
17 | console.log(age);
18 | ```
19 | **Output**
20 | ```
21 | Enter your age: 28
22 | 28
23 | ```
24 | ## Find the type
25 | ```js
26 | const age = prompt("Enter your age");
27 | console.log(age);
28 | console.log(typeof(age));
29 | ```
30 | **Output**
31 | ```
32 | Enter your age : 28
33 | Hello, Your age is 28
34 | "string"
35 | ```
36 | ***
37 | ```js
38 | const intValue = 5;
39 | console.log(typeof(intValue));
40 | 
41 | const floatValue = 5.5;
42 | console.log(typeof(floatValue));
43 | ```
44 | **Output**
45 | ```
46 | "number"
47 | "number"
48 | ```
49 | ***
50 | ```js
51 | const age = parseInt(prompt("Enter your age:"));
52 | console.log(age);
53 | console.log(typeof(age));
54 | ```
55 | **Output**
56 | ```
57 | Enter your age: 28
58 | "number"
59 | ```
60 | ## Float Input
61 | ```js
62 | const height = parseFloat(prompt('Enter your height '));
63 | console.log(height);
64 | console.log(typeof(height));
65 | ```
66 | **Output**
67 | ```
68 | Enter a number: 5.65
69 | 5.65
70 | "number"
71 | ```
72 | ## Error When Using paresInt() and parseFloat()
73 | ```js
74 | let name = parseInt(prompt('Enter your name: '));
75 | console.log(name);
76 | ```
77 | **Output**
78 | ```
79 | Enter your name: Punit
80 | NaN
81 | ```
82 | ***
83 | ## Programiz Quiz
84 | **What is the type of the ‘number’ variable?**
85 | ```js
86 | const number = prompt(‘Enter a random number’);
87 | console.log(typeof(number));
88 | ```
89 | 
90 | 1. number
91 | 2. string
92 | 3. NaN
93 | 4. undefined
94 | 
95 | Answer: 2
96 | 
97 | 
98 | 
99 | 


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/4. JavaScript Comments.md:
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 1 | # 4. JavaScript Comments
 2 | 
 3 | ## Write Comment
 4 | ```js
 5 | // program to take the user's name
 6 | let name = prompt("Enter your name: ");
 7 | console.log("Name: " + name);
 8 | ```
 9 | ## 
10 | **Output**
11 | ```
12 | Enter your name: James
13 | Name: James
14 | ```
15 | ## Another comment example
16 | ```js
17 | // program to take the user's name
18 | let name = prompt("Enter your name: ");  // take input
19 | console.log("Name: " + name); // print the name variable
20 | ```
21 | **Output**
22 | ```
23 | Enter your name: James
24 | Name: James
25 | ```
26 | ## Prevent Executing Code Using Comments
27 | ```js
28 | // program to take user's name and age
29 | let name = prompt("Enter a name: ");
30 | // let age = prompt("Enter age: ");
31 | console.log("name: " + name);
32 | // console.log("age:", age);
33 | ```
34 | **Output**
35 | ```
36 | Enter name: Sarah
37 | name: Sarah
38 | ```
39 | ***
40 | ## JavaScript Multiline comments
41 | ```js
42 | /*This program is used to take name of the user
43 | You can get the name from the user
44 | and display the result*/ 
45 | 
46 | let name = prompt("Enter your name:");
47 | console.log("Name " + name);
48 | ```
49 | **Output**
50 | ```
51 | Enter your name: Sarah
52 | Name Sarah
53 | ```
54 | ***
55 | ## Programmiz Quiz
56 | **Which of the following operators is used as a comment in JavaScript?**
57 | ```
58 | 1. //
59 | 2. <!-- →
60 | 3. #
61 | 4. **
62 | ```
63 | Answer: 1
64 | 
65 | 


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/5. JavaScript Operators and Arithmetic operators.md:
--------------------------------------------------------------------------------
  1 | # 5. JavaScript Operators and Arithmetic operators
  2 | ## Addition Operator
  3 | ```js
  4 | const x = 8;
  5 | const y = 4;
  6 | const result = x + y;
  7 | console.log(result);
  8 | ```
  9 | **Output**
 10 | ```
 11 | 12
 12 | ```
 13 | ```js
 14 | const x = 8;
 15 | const y = 4;
 16 | console.log(x + y);
 17 | ```
 18 | **Output**
 19 | ```
 20 | 12
 21 | ```
 22 | ## Float Values
 23 | ```js
 24 | const x = 8.5;
 25 | const y = 4;
 26 | const result = x + y;
 27 | console.log(result);
 28 | ```
 29 | **Output**
 30 | ```
 31 | 12.5
 32 | ```
 33 | ## Addition with Strings
 34 | ```js
 35 | const text1 = 'JavaScript';
 36 | const text2 = 'Programming';
 37 | console.log(text1 + text2);
 38 | ```
 39 | **Output**
 40 | ```
 41 | JavaScriptProgramming
 42 | ```
 43 | ## Subtraction Operator
 44 | ```js
 45 | const x = 8;
 46 | const y = 4;
 47 | const result = x - y;
 48 | console.log(result);
 49 | ```
 50 | **Output**
 51 | ```
 52 | 4
 53 | ```
 54 | ## Multiplication Operator
 55 | ```js
 56 | const x = 8;
 57 | const y = 4;
 58 | const result = x * y;
 59 | console.log(result);
 60 | ```
 61 | **Output**
 62 | ```
 63 | 32
 64 | ```
 65 | ## Division Operator
 66 | ```js
 67 | const x = 8;
 68 | const y = 4;
 69 | const result = x / y;
 70 | console.log(result);
 71 | ```
 72 | **Output**
 73 | ```
 74 | 2
 75 | ```
 76 | ## Modulus Operator
 77 | ```js
 78 | const x = 8;
 79 | const y = 4;
 80 | const result = x % y;
 81 | console.log(result);
 82 | ```
 83 | **Output**
 84 | ```
 85 | 0
 86 | ```
 87 | ```js
 88 | const x = 11;
 89 | const y = 4;
 90 | const result = x % y;
 91 | console.log(result);
 92 | ```
 93 | **Output**
 94 | ```
 95 | 3
 96 | ```
 97 | ## Increment Operator
 98 | ```js
 99 | let x = 8;
100 | console.log(++x);
101 | ```
102 | **Output**
103 | ```
104 | 9
105 | ```
106 | ```js
107 | let x = 8;
108 | console.log(x++);
109 | ```
110 | **Output**
111 | ```
112 | 8
113 | ```
114 | ```js
115 | let x = 8;
116 | console.log(x++);
117 | console.log(x);
118 | ```
119 | **Output**
120 | ```
121 | 8
122 | 9
123 | ```
124 | ## Decrement Operator
125 | ```js
126 | let x = 8;
127 | console.log(--x);
128 | ```
129 | **Output**
130 | ```
131 | 7
132 | ```
133 | ```js
134 | let x = 8;
135 | console.log(x--);
136 | console.log(x);
137 | ```
138 | **Output**
139 | ```
140 | 8
141 | 7
142 | ```
143 | ## Exponentiation Operator
144 | ```js
145 | let x = 8;
146 | const result = x ** 2;
147 | console.log(result);
148 | ```
149 | **Output**
150 | ```
151 | 64
152 | ```
153 | ## Multiple Operators
154 | ```js
155 | const result = 4 / 2 + 3 * 5 - 1;
156 | console.log(result);
157 | ```
158 | **Output**
159 | ```
160 | 16
161 | ```
162 | ***
163 | ## Practical Examples
164 | ```js
165 | const initialFee = 4535;
166 | const discountPercent = 10;
167 | 
168 | const discountAmount = discountPercent/100 * initialFee;
169 | const totalFee = initialFee - discountAmount;
170 | 
171 | console.log(`Fee after discount: ${totalFee} dollars`);
172 | ```
173 | **Output**
174 | ```
175 | Fee after discount: 4081.5 dollars
176 | ```
177 | ***
178 | ```js
179 | const kmDistance = 5;
180 | 
181 | const converstionRatio = 0.621371;
182 | const milesDistance = kmDistance * converstionRatio;
183 | 
184 | console.log('You covered ' + milesDistance + ' miles.');
185 | ```
186 | **Output**
187 | ```
188 | You covered 3.106855 miles.
189 | ```
190 | ***
191 | ## Programming Task
192 | **Create a program that converts degree celsius to fahrenheit.
193 | The formula to convert celsius to fahrenheit is
194 | Formula: fahrenheit = celsius * 1.8 + 32.
195 | What you can do is store the value of celsius value in the celsius variable. Then use the formula fahrenheit = celsius * 1.8 + 32 to convert celsius to fahrenheit and display the result.**
196 | ### Solution:
197 | ```js
198 | let celcius = 88;
199 | let fahrenheit = celcius * 1.8 + 32;
200 | console.log(`${celcius} celcius equals to ${fahrenheit} fahrenheit`);
201 | ```
202 | **Output**
203 | ```
204 | 88 celcius equals to 190.4 fahrenheit
205 | ```
206 | ***
207 | ## Programiz Quiz
208 | **Q. What is the output of the following code?**
209 | ```js
210 | console.log(5**3);
211 | ```
212 | 1. 555
213 | 2. 15
214 | 3. 125
215 | 4. 8
216 | 
217 | Answer: 3
218 | 


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/6. Booleans and Boolean Expression.md:
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  1 | # 6. Booleans and Boolean Expression
  2 | ## JavaScript Booleans
  3 | ```js
  4 | const value1 = true;
  5 | const value2 = false;
  6 | 
  7 | console.log(value1);
  8 | console.log(value2);
  9 | ```
 10 | **Output**
 11 | ```
 12 | true
 13 | false
 14 | ```
 15 | ## To know the type of data
 16 | ```js
 17 | const value1 = true;
 18 | const value2 = false;
 19 | console.log(value1);
 20 | console.log(value2);
 21 | console.log(typeof(value1));
 22 | console.log(typeof(value2));
 23 | ```
 24 | **Output**
 25 | ```
 26 | true
 27 | false
 28 | boolean
 29 | boolean
 30 | ```
 31 | ***
 32 | ## true and false shouldn't be used inside quotes
 33 | ```js
 34 | const value1 = "true";
 35 | const value2 = "false";
 36 | console.log(value1);
 37 | console.log(value2);
 38 | console.log(typeof(value1));
 39 | console.log(typeof(value2));
 40 | ```
 41 | **Output**
 42 | ```
 43 | true
 44 | false
 45 | string
 46 | string
 47 | ```
 48 | ***
 49 | ## JavaScript is a case-sensitive
 50 | ```js
 51 | const value1 = True;
 52 | const value2 = False;
 53 | console.log(value1);
 54 | console.log(value2);
 55 | ```
 56 | **Output**
 57 | ```
 58 | ReferenceError: Can't find variable: True
 59 | ```
 60 | ## Comparison Operators
 61 | ### Greater Than Operators
 62 | ```js
 63 | console.log(8  > 5);
 64 | ```
 65 | **Output**
 66 | ```
 67 | true
 68 | ```
 69 | ### Less Than Operator
 70 | ```js
 71 | console.log(3 < 5);
 72 | ```
 73 | **Output**
 74 | ```
 75 | true
 76 | ```
 77 | ### Greater Than or Equal Operator
 78 | ```js
 79 | console.log(5 >= 5);
 80 | ```
 81 | **Output**
 82 | ```
 83 | true
 84 | ```
 85 | ### Equal to Operator
 86 | ```js
 87 | console.log(5 == 5);
 88 | ```
 89 | **Output**
 90 | ```
 91 | true
 92 | ```
 93 | ***
 94 | ## Not Equal to Operator
 95 | ```js
 96 | console.log(5 != 5);
 97 | ```
 98 | **Output**
 99 | ```
100 | false
101 | ```
102 | ***
103 | ### Strict equal to Operator
104 | ```js
105 | console.log("5" === 5);
106 | ```
107 | **Output**
108 | ```
109 | false
110 | ```
111 | ***
112 | ## Comparison Between Variables
113 | ```js
114 | const number1 = 5;
115 | const number2 = 9;
116 | 
117 | const result = number1 < number2;
118 | console.log(result);
119 | ```
120 | **Output**
121 | ```
122 | true
123 | ```
124 | ***
125 | ## JavaScript Logical Operators
126 | ### JavaScript AND Operator
127 | ```js
128 | const age = 18;
129 | const height = 5.5;
130 | let result = age >= 18 && height > 5;
131 | console.log(result);
132 | ```
133 | **Output**
134 | ```
135 | true
136 | ```
137 | ### JavaScript OR Operator
138 | ```js
139 | let age = 18;
140 | let height = 5.5;
141 | let result = age >= 18 || height < 5;
142 | console.log(result);
143 | ```
144 | **Output**
145 | ```
146 | true
147 | ```
148 | ### JavaScript NOT Operator
149 | ```js
150 | const height = 5.5;
151 | const result = height < 6;
152 | console.log(!result);
153 | ```
154 | **Output**
155 | ```
156 | false
157 | ```
158 | ***
159 | ## Programmiz Quiz
160 | **Q. Which of the following code returns true?**
161 | 1. 5 == -5
162 | 2. 5 == '5'
163 | 3. 5 === '5'
164 | 4. 5 === -5
165 | ```
166 | Answer: 2
167 | ```
168 | 
169 | 
170 | 


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/7. Basic Type conversion.md:
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  1 | # 7. Basic Type conversion
  2 | ## Type Conversions
  3 | ```js
  4 | const x = 8;
  5 | const y = 4;
  6 | const result = x + y;
  7 | console.log(result);
  8 | ```
  9 | **Output**
 10 | ```
 11 | 12
 12 | ```
 13 | ***
 14 | ```js
 15 | const x = '8';
 16 | const y = 4;
 17 | const result = x + y;
 18 | console.log(result);
 19 | ```
 20 | **Output**
 21 | ```
 22 | 84
 23 | ```
 24 | ***
 25 | ```js
 26 | const x = '8';
 27 | const y = 4;
 28 | const result = x + y;
 29 | console.log(result);
 30 | console.log(typeof(result));
 31 | ```
 32 | **Output**
 33 | ```
 34 | 84
 35 | string
 36 | ```
 37 | ***
 38 | ```js
 39 | const x = 'hello';
 40 | const y = 4;
 41 | const result = x + y;
 42 | console.log(result);
 43 | ```
 44 | **Output**
 45 | ```
 46 | hello4
 47 | ```
 48 | ***
 49 | ```js
 50 | const result1 = '5' - '2';
 51 | const result2 = '5' - 2;
 52 | const result3 = '5' * 2;
 53 | const result4 = '5' / 2;
 54 | 
 55 | console.log(result1);
 56 | console.log(result2);
 57 | console.log(result3);
 58 | console.log(result4);
 59 | ```
 60 | **Output**
 61 | ```
 62 | 3
 63 | 3
 64 | 10
 65 | 2.5
 66 | ```
 67 | ***
 68 | ```js
 69 | const result1 = '5' - '2';
 70 | const result2 = '5' - 2;
 71 | const result3 = '5' * 2;
 72 | const result4 = '5' / 2;
 73 | 
 74 | console.log(result1);
 75 | console.log(result2);
 76 | console.log(result3);
 77 | console.log(result4);
 78 | 
 79 | console.log(typeof(result1));
 80 | console.log(typeof(result2));
 81 | console.log(typeof(result3));
 82 | console.log(typeof(result4));
 83 | ```
 84 | **Output**
 85 | ```
 86 | 3
 87 | 3
 88 | 10
 89 | 2.5
 90 | number
 91 | number
 92 | number
 93 | number
 94 | ```
 95 | ***
 96 | ```js
 97 | const result = '4' - 'hello';
 98 | console.log(result);
 99 | ```
100 | **Output**
101 | ```
102 | NaN
103 | ```
104 | ***
105 | ```js
106 | const result1 = '4' - true;
107 | console.log(result1);
108 | 
109 | const result2 = '4' + true;
110 | console.log(result2);
111 | 
112 | const result3 = 4 + false;
113 | console.log(result3);
114 | ```
115 | **Output**
116 | ```
117 | 3
118 | 4true
119 | 4
120 | ```
121 | ***
122 | ## JavaScript Explicit Conversion
123 | ### Explicit Numeric Conversion
124 | ```js
125 | const result = Number('324');
126 | console.log(result);
127 | 
128 | console.log(typeof(result));
129 | ```
130 | **Output**
131 | ```
132 | 324
133 | number
134 | ```
135 | ***
136 | ```js
137 | const result = Number(true);
138 | console.log(result);
139 | 
140 | console.log(typeof(result));
141 | ```
142 | **Output**
143 | ```
144 | 1
145 | number
146 | ```
147 | ***
148 | ### Convert to String Explicitly
149 | ```js
150 | const result = String(257);
151 | console.log(result);
152 | 
153 | console.log(typeof(result));
154 | ```
155 | **Output**
156 | ```
157 | 257
158 | string
159 | ```
160 | ***
161 | ```js
162 | const result1 = String(true);
163 | console.log(result1);
164 | 
165 | console.log(typeof(result1));
166 | 
167 | const result2 = String(false);
168 | console.log(result2);
169 | 
170 | console.log(typeof(result2));
171 | ```
172 | **Output**
173 | ```
174 | true
175 | string
176 | false
177 | string
178 | ```
179 | ***
180 | ```js
181 | const result = (257).toString();
182 | console.log(result);
183 | 
184 | console.log(typeof(result));
185 | ```
186 | **Output**
187 | ```
188 | 257
189 | string
190 | ```
191 | ***
192 | ### Programiz Quiz
193 | **Q. What is the output of the following code?**
194 | ```js
195 | console.log('5' - 3);
196 | ```
197 | 1. 2
198 | 2. 53
199 | 3. Error
200 | 4. NaN
201 | 
202 | Answer: 1
203 | 


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/8. if_else Statement.md:
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  1 | # if/else Statement
  2 | 
  3 | ## if statement
  4 | ### Syntax
  5 | ```
  6 | if (test_condition) {
  7 |     // if statement body
  8 | }
  9 | ```
 10 | ***
 11 | ```js
 12 | const score = parseInt(prompt('Enter your marks:'));
 13 | 
 14 | if (score >= 50) {
 15 |     console.log('You have passed your exams.');
 16 |     console.log('Congratulations.');
 17 | }
 18 | ```
 19 | **Output**
 20 | ```
 21 | Enter your marks: 80
 22 | You have passed your exams.
 23 | Congratulations.
 24 | ```
 25 | ***
 26 | 
 27 | ## Multiple if statement
 28 | ```js
 29 | const score = parseInt(prompt('Enter your marks:'));
 30 | 
 31 | if (score >= 50) {
 32 |     console.log('You have passed your exams.');
 33 |     console.log('Congratulations.');
 34 | }
 35 | 
 36 | if (score < 50) {
 37 |     console.log('Sorry, you failed your exam.');
 38 | }
 39 | ```
 40 | **Output**
 41 | ```
 42 | Enter your marks: 40
 43 | Sorry, you failed your exam.
 44 | ```
 45 | ***
 46 | ## if...else Statement
 47 | ### Syntax
 48 | ```
 49 | if (condition) {
 50 |   // code inside if block
 51 | }
 52 | else {
 53 |   // code inside else block
 54 | }
 55 | ```
 56 | ***
 57 | ```js
 58 | const score = 40;
 59 | 
 60 | if (score >= 50) {
 61 |     console.log('You have passed your exams.');
 62 |     console.log('Congratulations.');
 63 | }
 64 | 
 65 | else {
 66 |     console.log('Sorry, you failed your exam.');
 67 | }
 68 | ```
 69 | **Output**
 70 | ```
 71 | Sorry, you failed your exam.
 72 | ```
 73 | ***
 74 | ## else if Statement
 75 | ### Syntax
 76 | ```
 77 | if (test_condition1) {
 78 |     // statements1
 79 | }
 80 | else if (test_condition2){
 81 |     // statements2
 82 | }
 83 | else {
 84 |     // statements3
 85 | }
 86 | ```
 87 | ***
 88 | ```js
 89 | const score = 40;
 90 | 
 91 | if (score > 100) {
 92 |     console.log('Score is invalid');
 93 | }
 94 | 
 95 | else if ( score < 0) {
 96 |   console.log('Score is invalid');
 97 | }
 98 | 
 99 | else if (score >= 50) {
100 |     console.log('You have passed your exams.');
101 |     console.log('Congratulations.');
102 | }
103 | else {
104 |     console.log('Sorry, you failed your exam.');
105 | }
106 | ```
107 | **Output**
108 | ```
109 | Sorry, you failed your exam.
110 | ```
111 | ***
112 | ```js
113 | const score = -45;
114 | 
115 | if (score > 100) {
116 |     console.log('Score is invalid');
117 | }
118 | 
119 | else if ( score < 0) {
120 |   console.log('Score is invalid');
121 | }
122 | 
123 | else if (score >= 50) {
124 |     console.log('You have passed your exams.');
125 |     console.log('Congratulations.');
126 | }
127 | else {
128 |     console.log('Sorry, you failed your exam.');
129 | }
130 | ```
131 | **Output**
132 | ```
133 | Score is invalid
134 | ```
135 | ***
136 | ### Logical OR operator
137 | ```js
138 | const score = -45;
139 | 
140 | if (score > 100 || score < 0) {
141 |     console.log('Score is invalid');
142 | }
143 | 
144 | else if (score >= 50) {
145 |     console.log('You have passed your exams.');
146 |     console.log('Congratulations.');
147 | }
148 | else {
149 |     console.log('Sorry, you failed your exam.');
150 | }
151 | ```
152 | **Output**
153 | ```
154 | Score is Invalid.
155 | ```
156 | ***
157 | ### Programming Task
158 | **Can you create a program to check whether a number is positive or negative or 0? To create this program, create a variable named number and assign a value to it based on the user input. Then using a if statement, check if the number variable is positive or negative or 0.
159 | If the number is positive, print "The number is positive."
160 | If the number is negative, print "The number is negative."
161 | (and) If the number is 0, print "The number is 0."**
162 | ### Solution:
163 | ```js
164 | const number = parseInt(prompt('Enter a number:'));
165 | 
166 | if (number > 0) {
167 |     console.log("The number is positive.");
168 | }
169 | 
170 | else if ( number < 0) {
171 |   console.log("The number is negative.");
172 | }
173 | 
174 | else {
175 |     console.log('The number is 0.');
176 | }
177 | ```
178 | **Output**
179 | ```
180 | Enter a number: 40
181 | The number is positive
182 | ```
183 | ***
184 | ### Programiz Quiz
185 | **Q. What is the output of the following code?**
186 | ```js
187 | const time = 15;
188 | 
189 | if (time < 10)
190 |   console.log("Good Morning");
191 | else if (time < 19) 
192 |   console.log("Good Evening");
193 | else if (time < 22)
194 |   console.log("Good Night");
195 | else
196 |   console.log("Invalid Time");
197 | ```
198 | 
199 | 1. Good Morning
200 | 2. Good Evening
201 | 3. Good Night
202 | 4. Invalid Time
203 | 
204 | Answer: 2
205 | 


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/9. Ternary Operator.md:
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 1 | # 9. Ternary Operator
 2 | 
 3 | ### Example 1
 4 | ```js
 5 | const age = 15;
 6 | (age >= 18) ?
 7 | console.log("can vote.") : console.log("cannot vote.");
 8 | ```
 9 | **Output**
10 | ```
11 | cannot vote.
12 | ```
13 | ***
14 | ### Example 2
15 | 
16 | ```js
17 | // ternary operator to check the eligibility to vote
18 | const age = 15;
19 | const result = (age >= 18) ? " can vote." : "cannot vote.";
20 | console.log(result);
21 | ```
22 | **Output**
23 | ```
24 | cannot vote.
25 | ```
26 | ***
27 | ### Programming Task
28 | **Can you create a program to check whether a number is positive or negative?**
29 | ### Solution:
30 | ```js
31 | const number = 10;
32 | const result = (number >= 0) ?
33 | "The number is positive" : "The number is negative";
34 | console.log(result);
35 | ```
36 | **Output**
37 | ```
38 | The number is positive
39 | ```
40 | ***
41 | ### Programiz Quiz
42 | **Q. What is the correct ternary equivalent of the following if...else statement?**
43 | ```js
44 | if (5 > 3) {
45 |   greater = 5;
46 | }
47 | else {
48 |   greater = 3;
49 | }
50 | ```
51 | 1. greater = 5 > 3 ? 3 : 5;
52 | 2. 5 > 3 ? greater = 5 : 3;
53 | 3. greater = 5 > 3 ? 5 : 3;
54 | 4. 5 > 3 ? greater = 3 : 5;
55 | 
56 | Answer: 3
57 | 


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2 | 


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