├── arrow.js
├── default.js
├── destructuring.js
├── keys.js
├── looping.js
├── more-arrow.js
├── spread.js
├── template.js
└── var-let-const.js


/arrow.js:
--------------------------------------------------------------------------------
 1 | // function declaration 
 2 | 
 3 | // function add (a, b){
 4 | //     const result = a + b;
 5 | //     return result;
 6 | // }
 7 | function add (a, b){
 8 |     return a + b;
 9 | }
10 | 
11 | // function expression 
12 | const add2 = function(a, b){
13 |     return a + b;
14 | }
15 | 
16 | // arrow function 
17 | const add3 = (a, b) => a + b;
18 | const add4 = (num1, num2, num3, num4) => num1 + num2 + num3 + num4;
19 | const multiply = (num1, num2) => num1 * num2;
20 | 
21 | // const sum = add3(5, 93);
22 | // const sum = add4(4,5,6,7)
23 | // console.log(sum);
24 | const mult = multiply(3, 12)
25 | console.log(mult)


--------------------------------------------------------------------------------
/default.js:
--------------------------------------------------------------------------------
 1 | // default --> if value is not provided, take this as a default.
 2 | function add(num1 = 99, num2 = 0){
 3 |     const result = num1 + num2 + num3;
 4 |     console.log(num1, num2, result);
 5 |     return  result;
 6 | }
 7 | 
 8 | // const sum = add(5, 7);
 9 | // const sum = add(5);
10 | const sum = add(5);
11 | 
12 | function fullName(first, last =''){
13 |     const full = first + ' ' + last;
14 |     return full;
15 | }
16 | 
17 | function friends(numbs = []){
18 | 
19 | }
20 | 
21 | function person(human = {}){
22 |     
23 | }


--------------------------------------------------------------------------------
/destructuring.js:
--------------------------------------------------------------------------------
 1 | const actor = {
 2 |     name: 'Ananata',
 3 |     age: 30,
 4 |     phone: '01717653844',
 5 |     money: 124545121545
 6 | }
 7 | // if right side is an object left side of destructuring will be object as well 
 8 | // use property name as a variable that contains the property value
 9 | const {phone, age: boyos} = actor
10 | 
11 | // const phone = actor.phone;
12 | // const name = actor.name;
13 | // const age = actor.age;
14 | 
15 | console.log(phone)
16 | console.log(phone)
17 | console.log(phone)
18 | console.log(phone)
19 | console.log(phone)
20 | console.log(boyos)
21 | 
22 | 
23 | // array destructuring. 
24 | const numbers = [45, 99]
25 | const [first, second] = numbers;
26 | const [x, y] = [12, 66];
27 | 
28 | // advanced
29 | function doubleThem(a, b){
30 |     return [a*2, b*2];
31 | }
32 | 
33 | const [prothom, ditiyo] = doubleThem(6, 9);
34 | console.log(prothom, ditiyo)


--------------------------------------------------------------------------------
/keys.js:
--------------------------------------------------------------------------------
 1 | const glass = { 
 2 |     name: 'glass', 
 3 |     color: 'golden', 
 4 |     price: 12, 
 5 |     isCleaned: true 
 6 | };
 7 | 
 8 | console.log(glass);
 9 | // all properties name
10 | const keys = Object.keys(glass);
11 | // [ 'name', 'color', 'price', 'isCleaned' ]
12 | 
13 | // all property values
14 | const values = Object.values(glass);
15 | // [ 'glass', 'golden', 12, true ]
16 | // console.log(values)
17 | 
18 | const entries = Object.entries(glass);
19 | // console.log(entries);
20 | // array of array, two dimensional array
21 | // [
22 | //     [ 'name', 'glass' ],
23 | //     [ 'color', 'golden' ],
24 | //     [ 'price', 12 ],
25 | //     [ 'isCleaned', true ]
26 | // ]
27 | 
28 | // delete glass.isCleaned;
29 | 
30 | const {isCleaned, ...shortGlass} = glass;
31 | // console.log(shortGlass);
32 | 
33 | // freeze 
34 | // Object.freeze(glass);
35 | Object.seal(glass);
36 | glass.source = 'Bangladesh';
37 | glass.price = 5000;
38 | delete glass.name;
39 | console.log(glass);
40 | 
41 | 
42 | 


--------------------------------------------------------------------------------
/looping.js:
--------------------------------------------------------------------------------
 1 | // for of use on array or string not in object
 2 | // for in use on object
 3 | 
 4 | const numbers = [1, 6, 8, 4];
 5 | // for(let i = 0; i < numbers.length; i++){}
 6 | // while
 7 | 
 8 | for(const num of numbers){
 9 |     // console.log(num);
10 | }
11 | 
12 | const nobab = 'Siraj Ud Doula';
13 | for(const char of nobab){
14 |     // console.log(char);
15 | }
16 | 
17 | const glass = { 
18 |     name: 'glass', 
19 |     color: 'golden', 
20 |     price: 12, 
21 |     isCleaned: true 
22 | };
23 | 
24 | // for(const key of glass){
25 | //     console.log(key)
26 | // }
27 | 
28 | for(const key in glass){
29 |     const value = glass[key];
30 |     // console.log(key, value)
31 | }
32 | 
33 | // optional
34 | const keys = Object.keys(glass);
35 | console.log(keys);
36 | 
37 | for(const key of keys){
38 |     const value = glass[key];
39 |     console.log(key, value)
40 | }


--------------------------------------------------------------------------------
/more-arrow.js:
--------------------------------------------------------------------------------
 1 | const difference = (x, y) => x - y;
 2 | const multiply = (first, second , third) => first * second * third;
 3 | 
 4 | // single parameter or one parameter 
 5 | const getAge = (person) => person.age;
 6 | const student = { name: 'ananata', age: 45}
 7 | const age = getAge(student)
 8 | console.log(age);
 9 | 
10 | const getThird = numbers => numbers[2];
11 | const third = getThird([5,9,88,2,13])
12 | console.log(third)
13 | 
14 | const doubleIt = num => num * 2;
15 | 
16 | // no parameter
17 | const getPI = () => Math.PI
18 | console.log(getPI())
19 | 
20 | // large arrow function. if you want to get anything returned from this function. then you have to use the return keyword  
21 | const doMath = (x, y, Z) => {
22 |     const sum = x + y + z;
23 |     const mult = x * y * z;
24 |     const result = sum + mult
25 |     return result
26 | }


--------------------------------------------------------------------------------
/spread.js:
--------------------------------------------------------------------------------
 1 | const max = Math.max(6, 23, 45, 1, 89, 23)
 2 | const numbers = [3, 5, 2, 45, 5, 43, 90, 32, 15];
 3 | const arrayMax = Math.max(...numbers);
 4 | // console.log(...numbers)
 5 | console.log(arrayMax)
 6 | 
 7 | // use spread operator to copy
 8 | const friends = [4, 5, 87, 9];
 9 | const bondhu = friends;
10 | const dosto = [...friends] // copy
11 | console.log(dosto)
12 | friends.push(100)
13 | console.log(dosto)
14 | console.log(friends)
15 | 
16 | // advanced 
17 | const sonkha = [...friends, 9999] // add extra elements while copy
18 | console.log(sonkha)


--------------------------------------------------------------------------------
/template.js:
--------------------------------------------------------------------------------
 1 | const first = 'Jaan'
 2 | const last = 'pakhi'
 3 | const greet = 'Potas potas';
 4 | const name = first + ' ' + last + " " + greet;
 5 | console.log(name);
 6 | const a = 10;
 7 | const b = 20;
 8 | const  result = 'The sum of ' + a + ' and ' + b + ' is ' + (a + b);
 9 | console.log(result);  
10 | 
11 | const numbers = [45, 48, 98,78]
12 | const student = {name: 'john ochena', age: 5}
13 | // const math = `The sum of ${numbers[0]} and ${b} is ${a + b}`
14 | const math = `The sum of ${numbers[0]} and ${student.age} is ${numbers[0] + student.age}`
15 | console.log(math)
16 | 
17 | const email = 'Hi john \n' + 
18 | 'cena cena lage \n'+
19 | 'tumi mara mari korba naki'
20 | ;
21 | console.log(email)
22 | 
23 | const challenge = `John Cena
24 | cena naki ochena
25 | mair dimu prochur`;
26 | console.log(challenge)


--------------------------------------------------------------------------------
/var-let-const.js:
--------------------------------------------------------------------------------
 1 | // var : no reason to use var
 2 | // let : allow it to reassign
 3 | // const: do not allow it to reassign
 4 | 
 5 | const money = 25;
 6 | // money = 50;
 7 | const rich = money + 25;
 8 | console.log(rich);
 9 | 
10 | let count = 0;
11 | count = count + 10;
12 | console.log(count)
13 | 
14 | const numbers = [23, 4, 23, 12, 56];
15 | // numbers = [4, 5, 7, 7];
16 | numbers[1] = 55;
17 | numbers.push(8, 9, 65);
18 | 
19 | console.log(numbers);
20 | 
21 | // object 
22 | const student = {
23 |     name: 'moyna pakhi',
24 |     class: 12
25 | }
26 | 
27 | // student = {name:'kokil konthi'}
28 | student.name = 'moyur konthi';
29 | console.log(student);
30 | 
31 | // loop
32 | let sum = 0;
33 | for(let i = 0; i <10; i++){
34 |     const num = i;
35 |     sum = sum + num;
36 | }
37 | console.log(sum);


--------------------------------------------------------------------------------