├── src ├── main │ └── java │ │ └── com │ │ └── in28minutes │ │ └── java │ │ └── beginners │ │ ├── concept │ │ └── examples │ │ │ ├── oops │ │ │ ├── interfaces │ │ │ │ ├── Flyable.java │ │ │ │ ├── Bird.java │ │ │ │ ├── Aeroplane.java │ │ │ │ ├── InterfaceExamples.java │ │ │ │ ├── InterfaceWithMain.java │ │ │ │ └── IntefaceRules.java │ │ │ ├── inheritance │ │ │ │ ├── InheritanceExamples.java │ │ │ │ └── EveryClassExtendsObject.java │ │ │ ├── cohesion │ │ │ │ ├── problem │ │ │ │ │ └── CohesionExampleProblem.java │ │ │ │ └── solution │ │ │ │ │ └── CohesionExampleSolution.java │ │ │ ├── encapsulation │ │ │ │ └── EncapsulationExample.java │ │ │ └── coupling │ │ │ │ ├── solution │ │ │ │ └── CouplingExamplesSolution.java │ │ │ │ └── problem │ │ │ │ └── CouplingExamplesProblem.java │ │ │ ├── basics │ │ │ ├── Cricketer.java │ │ │ ├── CricketScorer.java │ │ │ └── Actor.java │ │ │ ├── membermodifiers │ │ │ ├── access │ │ │ │ ├── ExampleClass.java │ │ │ │ ├── SubClassInSamePackage.java │ │ │ │ └── TestClassInSamePackage.java │ │ │ └── nonaccess │ │ │ │ ├── FinalMemberModifiersExample.java │ │ │ │ └── StaticModifierExamples.java │ │ │ ├── others │ │ │ ├── SameType.java │ │ │ └── PrintfExamples.java │ │ │ ├── operators │ │ │ ├── TernaryOperator.java │ │ │ ├── StringConcatenationExamples.java │ │ │ ├── IncrementAndDecrementOperators.java │ │ │ ├── InstanceOfExamples.java │ │ │ ├── RelationalOperators.java │ │ │ └── LogicalOperators.java │ │ │ ├── object │ │ │ ├── ToStringExamples.java │ │ │ └── EqualsHashCodeExamples.java │ │ │ ├── collections │ │ │ ├── FailFast.java │ │ │ └── FailSafe.java │ │ │ ├── flow │ │ │ ├── DoWhileLoopExamples.java │ │ │ ├── WhileLoopExamples.java │ │ │ ├── ForLoopExample.java │ │ │ ├── BreakExamples.java │ │ │ ├── ContinueExamples.java │ │ │ └── SwitchExamples.java │ │ │ ├── threads │ │ │ ├── ThreadWaitAndNotify.java │ │ │ ├── ThreadDeadlock.java │ │ │ ├── ThreadExampleSynchronized.java │ │ │ └── ExecutorServiceExamples.java │ │ │ ├── files │ │ │ └── ConsoleExamples.java │ │ │ ├── logging │ │ │ └── LoggerExample.java │ │ │ ├── variables │ │ │ ├── PassingVariablesToMethods.java │ │ │ ├── StaticAndMemberVariables.java │ │ │ └── VariableInitialization.java │ │ │ ├── serialization │ │ │ ├── SerializationExamples2.java │ │ │ ├── SerializationExamples3.java │ │ │ └── SerializationExamples.java │ │ │ ├── enums │ │ │ ├── EnumAdvanced2.java │ │ │ ├── Enum.java │ │ │ └── EnumAdvanced.java │ │ │ ├── exceptionhandling │ │ │ └── ExceptionHandlingExample2.java │ │ │ ├── innerclass │ │ │ └── AnonymousClass.java │ │ │ ├── string │ │ │ ├── StringBufferBuilderExamples.java │ │ │ └── StringExamples.java │ │ │ ├── initializers │ │ │ └── InitializerExamples.java │ │ │ ├── varargs │ │ │ └── VariableArgumentExamples.java │ │ │ ├── reflection │ │ │ └── ReflectionExamples.java │ │ │ └── generics │ │ │ ├── GenericsExamples.java │ │ │ └── GenericsExamples2.java │ │ ├── simple │ │ └── design │ │ │ └── patterns │ │ │ ├── MySingletonUsingEnum.java │ │ │ ├── SingletonPattern.java │ │ │ ├── ObserverPattern.java │ │ │ ├── StrategyPattern.java │ │ │ ├── FactoryPattern.java │ │ │ ├── AdapterPattern.java │ │ │ ├── BuilderPattern.java │ │ │ └── StatePattern.java │ │ └── program │ │ └── examples │ │ ├── number │ │ ├── DisplayNumbersInReverse.java │ │ ├── CelsiusFahrenheitConverter.java │ │ ├── CompoundInterest.java │ │ ├── SimpleInterest.java │ │ ├── DisplayLowerCaseAlphabets.java │ │ ├── DisplayUpperCaseAlphabets.java │ │ ├── DivisorsOfNumber.java │ │ ├── PowerFunction.java │ │ ├── FindNCR.java │ │ ├── Factorial.java │ │ ├── FactorialRecursion.java │ │ ├── FindNPR.java │ │ ├── FloydTriangle.java │ │ ├── MultiplicationTable.java │ │ ├── FibonacciSeries.java │ │ ├── FibonacciSeriesRecursion.java │ │ ├── OddNumberCheck.java │ │ ├── EvenNumberCheck.java │ │ ├── SumOfFirstOddNumbers.java │ │ ├── SumOfFirstEvenNumbers.java │ │ ├── NumberOfDigits.java │ │ ├── LeapYear.java │ │ ├── ReverseNumber.java │ │ ├── SumOfFirstNNumbers.java │ │ ├── SumOfDigits.java │ │ ├── ArmstrongNumber.java │ │ ├── Palindrome.java │ │ ├── GreatestCommonDivisor.java │ │ ├── PascalTriangle.java │ │ ├── PrimeNumberCheck.java │ │ ├── PerfectNumberCheck.java │ │ ├── FindLCM.java │ │ ├── PrimeNumbersList.java │ │ ├── ComplexNumber.java │ │ └── CaesarCipherProgram.java │ │ ├── shapes │ │ ├── Square.java │ │ ├── Rectangle.java │ │ └── Circle.java │ │ ├── search │ │ ├── LinearSearch.java │ │ └── BinarySearch.java │ │ ├── arrays │ │ ├── PassingArrayToFunctionExample.java │ │ ├── ArrayReverse.java │ │ └── ArraysHelper.java │ │ ├── matrices │ │ ├── InverseOrTransposeOfMatrix.java │ │ ├── MatrixAddition.java │ │ ├── MatrixSubtraction.java │ │ ├── MatrixMultiplication.java │ │ └── DeterminantOfMatrix.java │ │ ├── sorting │ │ ├── BubbleSortAlgorithm.java │ │ ├── InsertionSortAlgorithm.java │ │ ├── SelectionSortAlgorithm.java │ │ ├── CountingSort.java │ │ ├── MergeSortAlgorithm.java │ │ ├── QuickSortAlgorithm.java │ │ └── RadixSort.html │ │ └── datastructures │ │ ├── Stack.java │ │ ├── Queue.java │ │ ├── CircularOrRingBuffer.java │ │ └── CircularQueue.java └── test │ └── java │ └── com │ └── in28minutes │ └── java │ └── beginner │ └── junit │ └── examples │ ├── hashmap │ └── HashMapTest.java │ ├── variables │ ├── InstanceVariableExample.java │ ├── LocalVariablesTest.java │ ├── StaticExample.java │ ├── InstanceVariableTest.java │ ├── AnonymousClassTest.java │ └── StaticVariableTest.java │ ├── maths │ └── MathTest.java │ ├── wrapper │ ├── CharacterWrapperTest.java │ └── BooleanWrapperTest.java │ ├── methodhiding │ └── MethodHidingTest.java │ ├── string │ └── StringVsStringBufferPerformanceTest.java │ ├── varargs │ └── VariableArgumentsTest.java │ ├── polymorphism │ ├── PolymorphismAbstractClassTest.java │ ├── MethodOverloadingTest.java │ └── PolymorphismBasicsTest.java │ ├── collection │ └── CollectionTest.java │ ├── abstractclass │ └── AbstractClassTest.java │ ├── constructors │ ├── ConstructorChainingTest.java │ ├── CopyConstructorTest.java │ ├── AbstractClassConstructorTest.java │ └── ConstructorBasicsTest.java │ ├── primitivedatatypes │ ├── BooleanExampleTest.java │ ├── IntegerTest.java │ ├── PrimitiveDataTypesTest.java │ ├── LongTest.java │ └── CharacterTest.java │ ├── innerclass │ ├── NestedClass.java │ └── NestedClassTest.java │ ├── controlflow │ ├── IfStatementTest.java │ └── SwitchStatementTest.java │ ├── loops │ ├── DoWhileLoopTest.java │ ├── EnhancedForLoopTest.java │ ├── ForLoopTest.java │ └── WhileLoopTest.java │ ├── functional │ └── programming │ │ └── LambdaExpressionsTest.java │ └── exception │ └── TryCatchTest.java ├── .gitignore └── pom.xml /src/main/java/com/in28minutes/java/beginners/concept/examples/oops/interfaces/Flyable.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.oops.interfaces; 2 | 3 | public interface Flyable { 4 | void fly(); 5 | } 6 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/oops/interfaces/Bird.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.oops.interfaces; 2 | public class Bird implements Flyable { 3 | public void fly() { 4 | System.out.println("Bird is flying"); 5 | } 6 | } 7 | -------------------------------------------------------------------------------- /src/test/java/com/in28minutes/java/beginner/junit/examples/hashmap/HashMapTest.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginner.junit.examples.hashmap; 2 | 3 | import org.junit.Test; 4 | 5 | public class HashMapTest { 6 | @Test 7 | public void hashMapCreation(){ 8 | 9 | } 10 | } 11 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/oops/interfaces/Aeroplane.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.oops.interfaces; 2 | 3 | public class Aeroplane implements Flyable { 4 | public void fly() { 5 | System.out.println("Aeroplane is flying"); 6 | } 7 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/oops/interfaces/InterfaceExamples.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.oops.interfaces; 2 | 3 | public class InterfaceExamples { 4 | public static void main(String[] args) { 5 | Flyable flyable = new Bird(); 6 | flyable.fly(); 7 | } 8 | } 9 | -------------------------------------------------------------------------------- /src/test/java/com/in28minutes/java/beginner/junit/examples/variables/InstanceVariableExample.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginner.junit.examples.variables; 2 | 3 | public class InstanceVariableExample { 4 | //Leaving Default access to have examples simple. 5 | //Ideally this variable should be private. 6 | int instanceVariable; 7 | } 8 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/simple/design/patterns/MySingletonUsingEnum.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.simple.design.patterns; 2 | 3 | public enum MySingletonUsingEnum { 4 | INSTANCE; 5 | private MySingletonUsingEnum() { 6 | System.out.println("Here"); 7 | } 8 | 9 | public String retrieveSomething() { 10 | return "DUMMY"; 11 | } 12 | 13 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/basics/Cricketer.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.basics; 2 | 3 | public class Cricketer { 4 | String name; 5 | int odiRuns; 6 | int testRuns; 7 | int t20Runs; 8 | 9 | public int totalRuns() { 10 | int totalRuns = odiRuns + testRuns + t20Runs; 11 | return totalRuns; 12 | } 13 | } 14 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/simple/design/patterns/SingletonPattern.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.simple.design.patterns; 2 | 3 | public class SingletonPattern { 4 | static class Singleton { 5 | private static Singleton instance = new Singleton(); 6 | 7 | private Singleton() { 8 | } 9 | 10 | public static Singleton getSingleInstance() { 11 | return instance; 12 | } 13 | 14 | } 15 | } -------------------------------------------------------------------------------- /src/test/java/com/in28minutes/java/beginner/junit/examples/maths/MathTest.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginner.junit.examples.maths; 2 | 3 | import static org.junit.Assert.*; 4 | 5 | import org.junit.Test; 6 | 7 | public class MathTest { 8 | 9 | @Test 10 | public void absoluteValue(){ 11 | assertEquals(1,Math.abs(-1)); 12 | assertEquals(1,Math.abs(1)); 13 | 14 | assertEquals(1.2,Math.abs(-1.2),0.0); 15 | assertEquals(1.2,Math.abs(1.2),0.0); 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/DisplayNumbersInReverse.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class DisplayNumbersInReverse { 4 | 5 | public static void showNumbersInReverseOrder(int number) { 6 | for(int i=number;i>=1;i--){ 7 | System.out.print(i + " "); 8 | } 9 | } 10 | 11 | public static void main(String[] args) { 12 | DisplayNumbersInReverse.showNumbersInReverseOrder(10); 13 | //10 9 8 7 6 5 4 3 2 1 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/CelsiusFahrenheitConverter.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class CelsiusFahrenheitConverter { 4 | private static double calculateFahrenheit(int celsius) { 5 | return (celsius*9) / 5.0 + 32; 6 | } 7 | 8 | public static void main(String args[]) { 9 | System.out.println(calculateFahrenheit(-40));//-40.0 10 | System.out.println(calculateFahrenheit(32));//89.6 11 | System.out.println(calculateFahrenheit(49));//120.2 12 | } 13 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/CompoundInterest.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class CompoundInterest { 4 | private static double calculateCompoundInterest( 5 | double principal, double rate, int years) { 6 | double amount = principal * Math.pow(1 + rate, years); 7 | return amount; 8 | } 9 | 10 | public static void main(String args[]) { 11 | System.out.println(calculateCompoundInterest( 12 | (double) 10000, .10, 20));//67274.99949325611 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/SimpleInterest.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class SimpleInterest { 4 | private static double calculateSimpleInterest( 5 | double principal, double rate, int years) { 6 | double amount = principal * (1 + rate * years); 7 | return amount; 8 | } 9 | 10 | public static void main(String args[]) { 11 | System.out.println(SimpleInterest 12 | .calculateSimpleInterest((double) 10000, 13 | .10, 20));//30000.0 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/DisplayLowerCaseAlphabets.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class DisplayLowerCaseAlphabets { 4 | 5 | public static void listLowerCaseAlphabets(int number) { 6 | for(char ch='a';ch<='z';ch++){ 7 | System.out.print(ch + " "); 8 | } 9 | } 10 | 11 | public static void main(String[] args) { 12 | DisplayLowerCaseAlphabets.listLowerCaseAlphabets(10); 13 | //a b c d e f g h i j k l m n o p q r s t u v w x y z 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/DisplayUpperCaseAlphabets.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class DisplayUpperCaseAlphabets { 4 | 5 | public static void showUpperCaseAlphabets(int number) { 6 | for(char ch='A';ch<='Z';ch++){ 7 | System.out.print(ch + " "); 8 | } 9 | } 10 | 11 | public static void main(String[] args) { 12 | DisplayUpperCaseAlphabets.showUpperCaseAlphabets(10); 13 | //A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/DivisorsOfNumber.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class DivisorsOfNumber { 4 | 5 | public static void printDivisorsOfNumber(int number) { 6 | for (int i = 1; i < number; i++) { 7 | boolean isDivisor = (number % i == 0); 8 | if (isDivisor) { 9 | System.out.print(i + " "); 10 | } 11 | } 12 | } 13 | 14 | public static void main(String[] args) { 15 | DivisorsOfNumber.printDivisorsOfNumber(28);//1 2 4 7 14 16 | 17 | } 18 | 19 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/membermodifiers/access/ExampleClass.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.membermodifiers.access; 2 | 3 | public class ExampleClass { 4 | int defaultVariable; 5 | public int publicVariable; 6 | private int privateVariable; 7 | protected int protectedVariable; 8 | 9 | void defaultMethod() { 10 | privateVariable = 5; 11 | } 12 | 13 | public void publicMethod() { 14 | 15 | } 16 | 17 | private void privateMethod() { 18 | 19 | } 20 | 21 | protected void protectedMethod() { 22 | 23 | } 24 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/PowerFunction.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class PowerFunction { 4 | public static long power(int number, int power) { 5 | long value = 1; 6 | for(int i=1;i<=power;i++){ 7 | value = value * number; 8 | } 9 | return value; 10 | } 11 | 12 | public static void main(String[] args) { 13 | System.out.println(PowerFunction 14 | .power(2, 5));//32 15 | System.out.println(PowerFunction 16 | .power(7, 5));//16807 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/test/java/com/in28minutes/java/beginner/junit/examples/wrapper/CharacterWrapperTest.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginner.junit.examples.wrapper; 2 | 3 | import static org.junit.Assert.assertFalse; 4 | import static org.junit.Assert.assertTrue; 5 | 6 | import org.junit.Test; 7 | 8 | public class CharacterWrapperTest { 9 | 10 | @Test 11 | public void characterIsDigitorLetter() { 12 | assertTrue(Character.isDigit('1')); 13 | assertFalse(Character.isDigit('A')); 14 | assertTrue(Character.isLetter('Z')); 15 | assertFalse(Character.isLetter(';')); 16 | } 17 | 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/FindNCR.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class FindNCR { 4 | public static int calculateNCR(int n, 5 | int r) { 6 | return factorial(n)/(factorial(n-r)*factorial(r)); 7 | } 8 | 9 | private static int factorial(int number) { 10 | int factorial = 1; 11 | for(int i=2;i<=number;i++){ 12 | factorial = factorial * i; 13 | } 14 | return factorial; 15 | } 16 | 17 | 18 | public static void main(String[] args) { 19 | System.out.println(FindNCR 20 | .calculateNCR(7, 3));//35 21 | } 22 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/oops/interfaces/InterfaceWithMain.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.oops.interfaces; 2 | 3 | 4 | public class InterfaceWithMain { 5 | public static void main(String[] args) { 6 | Bird bird = new Bird(); 7 | bird.fly();// Bird is flying 8 | 9 | Aeroplane aeroplane = new Aeroplane(); 10 | aeroplane.fly();// Aeroplane is flying 11 | 12 | // An interface reference variable can hold 13 | // objects of any implementation of interface 14 | Flyable flyable1 = new Bird(); 15 | Flyable flyable2 = new Aeroplane(); 16 | 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/others/SameType.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.others; 2 | 3 | public class SameType { 4 | } 5 | 6 | class SuperClass { 7 | 8 | } 9 | 10 | class SubClass extends SuperClass { 11 | 12 | } 13 | 14 | abstract class Abstract { 15 | abstract SuperClass method1(); 16 | } 17 | 18 | interface Interface { 19 | SuperClass method2(); 20 | } 21 | 22 | class ConcreteClass extends Abstract implements Interface { 23 | 24 | public SubClass method2() { 25 | return null; 26 | } 27 | 28 | SubClass method1() { 29 | return null; 30 | } 31 | 32 | } 33 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/shapes/Square.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.shapes; 2 | 3 | public class Square { 4 | private int side; 5 | 6 | public Square(int side) { 7 | super(); 8 | this.side = side; 9 | } 10 | 11 | public int calculateArea() { 12 | return side * side; 13 | } 14 | 15 | public int calculatePerimeter() { 16 | return 4 * side; 17 | } 18 | 19 | public static void main(String[] args) { 20 | Square square = new Square(15); 21 | System.out.println(square.calculateArea());//225 22 | System.out.println(square.calculatePerimeter());//60 23 | } 24 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/membermodifiers/access/SubClassInSamePackage.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.membermodifiers.access; 2 | 3 | public class SubClassInSamePackage extends ExampleClass { 4 | 5 | void subClassMethod() { 6 | publicVariable = 5; 7 | publicMethod(); 8 | 9 | // privateVariable is not visible to SubClass 10 | // Below Line, uncommented, would give compiler error 11 | // privateVariable=5; //COMPILE ERROR 12 | // privateMethod(); 13 | 14 | protectedVariable = 5; 15 | protectedMethod(); 16 | 17 | defaultVariable = 5; 18 | defaultMethod(); 19 | } 20 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/operators/TernaryOperator.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.operators; 2 | 3 | //1.D 2.C 3.B 4.C 5.E 6.C 7.E 8.B 9.D 10.A 11.D 12.D 13.B 14.A 15.C 16.B 17.D 18.C 19.E 20.D 21.D 22.A 23.A 24.C 25.B 4 | class TernaryOperator { 5 | public static void main(String[] args) { 6 | int age = 18; 7 | // syntax - booleanCondition?ResultIfTrue:ResultIfFalse; 8 | System.out.println(age >= 18 ? "Can Vote" : "Cannot Vote");// Can Vote 9 | 10 | age = 15; 11 | System.out.println(age >= 18 ? "Can Vote" : "Cannot Vote");// Cannot 12 | // Vote 13 | } 14 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/Factorial.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class Factorial { 4 | 5 | public static long factorial(int number) { 6 | long factorial = 1; 7 | for(int i=1;i<=number;i++){ 8 | factorial = factorial * i; 9 | } 10 | return factorial; 11 | } 12 | 13 | public static void main(String[] args) { 14 | System.out.println(Factorial.factorial(0));//1 15 | System.out.println(Factorial.factorial(2));//2 16 | System.out.println(Factorial.factorial(5));//120 17 | System.out.println(Factorial.factorial(10));//3628880 18 | } 19 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/search/LinearSearch.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.search; 2 | 3 | public class LinearSearch { 4 | 5 | public static int search(int numbers[],int numberToFind){ 6 | 7 | for(int i = 0;i< numbers.length;i++){ 8 | if(numbers[i]==numberToFind){ 9 | return i; 10 | } 11 | } 12 | 13 | return -1; 14 | } 15 | 16 | public static void main(String[] args) { 17 | System.out.println(LinearSearch.search(new int[]{1}, 15)); //-1 18 | System.out.println(LinearSearch.search(new int[]{15,2,3,8,7}, 3));//2 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/FactorialRecursion.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class FactorialRecursion { 4 | 5 | public static long factorial(int number) { 6 | if(number<=1) return 1; //base condition 7 | return number * factorial(number-1); 8 | } 9 | 10 | public static void main(String[] args) { 11 | System.out.println(FactorialRecursion.factorial(0));//1 12 | System.out.println(FactorialRecursion.factorial(2));//2 13 | System.out.println(FactorialRecursion.factorial(5));//120 14 | System.out.println(FactorialRecursion.factorial(10));//3628880 15 | } 16 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/oops/inheritance/InheritanceExamples.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.oops.inheritance; 2 | 3 | abstract class Animal { 4 | String name; 5 | 6 | // cool functionality 7 | abstract String bark(); 8 | } 9 | 10 | class Dog extends Animal { 11 | String bark() { 12 | return "Bow Bow"; 13 | } 14 | } 15 | 16 | class Cat extends Animal { 17 | String bark() { 18 | return "Meow Meow"; 19 | } 20 | } 21 | 22 | public class InheritanceExamples { 23 | public static void main(String[] args) { 24 | Animal animal = new Dog(); 25 | System.out.println(animal.bark()); 26 | } 27 | } 28 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/FindNPR.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class FindNPR { 4 | public static int calculateNPR(int n, 5 | int r) { 6 | return factorial(n)/factorial(r); 7 | } 8 | 9 | private static int factorial(int number) { 10 | int factorial = 1; 11 | for(int i=2;i<=number;i++){ 12 | factorial = factorial * i; 13 | } 14 | return factorial; 15 | } 16 | 17 | 18 | public static void main(String[] args) { 19 | System.out.println(FindNPR 20 | .calculateNPR(7, 3));//840 21 | System.out.println(FindNPR 22 | .calculateNPR(8, 1));//40320 23 | } 24 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/object/ToStringExamples.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.object; 2 | 3 | class Animal { 4 | 5 | public Animal(String name, String type) { 6 | this.name = name; 7 | this.type = type; 8 | } 9 | 10 | String name; 11 | String type; 12 | 13 | @Override 14 | public String toString() { 15 | return "Animal [name=" + name + ", type=" + type + "]"; 16 | } 17 | } 18 | 19 | public class ToStringExamples { 20 | public static void main(String[] args) { 21 | Animal animal = new Animal("Tommy", "Dog"); 22 | System.out.println(animal);// Animal [name=Tommy, type=Dog] 23 | } 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/FloydTriangle.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class FloydTriangle { 4 | 5 | private static void printFloydTriangle(int numberOfRows) { 6 | int number = 1; 7 | for (int row = 1; row <= numberOfRows; row++) { 8 | for (int index = 1; index <= row; index++) { 9 | System.out.print(number + " "); 10 | number++; 11 | } 12 | System.out.println(); 13 | } 14 | } 15 | 16 | public static void main(String[] args) { 17 | printFloydTriangle(5); 18 | // 1 19 | // 2 3 20 | // 4 5 6 21 | // 7 8 9 10 22 | // 11 12 13 14 15 23 | 24 | } 25 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/MultiplicationTable.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | class MultiplicationTable { 4 | 5 | private static void printMultiplicationTable( 6 | int number, int upto) { 7 | for (int c = 1; c <= upto; c++) 8 | System.out.println(number + "*" + c + " = " 9 | + (number * c)); 10 | } 11 | 12 | public static void main(String args[]) { 13 | MultiplicationTable.printMultiplicationTable(7, 10); 14 | /* 15 | * 7*1 = 7 16 | 7*2 = 14 17 | 7*3 = 21 18 | 7*4 = 28 19 | 7*5 = 35 20 | 7*6 = 42 21 | 7*7 = 49 22 | 7*8 = 56 23 | 7*9 = 63 24 | 7*10 = 70 25 | */ 26 | } 27 | 28 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/collections/FailFast.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.collections; 2 | 3 | import java.util.HashMap; 4 | import java.util.Iterator; 5 | import java.util.Map; 6 | 7 | public class FailFast { 8 | 9 | public static void main(String[] args) { 10 | Map map = new HashMap(); 11 | map.put("key1", "value1"); 12 | map.put("key2", "value2"); 13 | map.put("key3", "value3"); 14 | 15 | Iterator iterator = map.keySet().iterator(); 16 | 17 | while (iterator.hasNext()) { 18 | System.out.println(map.get(iterator.next())); 19 | map.put("key4", "value4"); 20 | } 21 | 22 | } 23 | 24 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/concept/examples/flow/DoWhileLoopExamples.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.concept.examples.flow; 2 | 3 | public class DoWhileLoopExamples { 4 | public static void main(String[] args) { 5 | int count = 0; 6 | // do while also is used when it is not clear how many times loop has to 7 | // be executed. 8 | do { 9 | System.out.print(count); 10 | count++; 11 | } while (count < 5);// while this condn is true, loop is executed. 12 | // output is 01234 13 | 14 | // Code in do while is executed atleast once. 15 | count = 5; 16 | do { 17 | System.out.print(count); 18 | count++; 19 | } while (count < 5); 20 | // output is 5 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/FibonacciSeries.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class FibonacciSeries { 4 | 5 | public static void generateSeriesUpto(int limit) { 6 | int firstNumber = 0; 7 | int secondNumber = 1; 8 | 9 | System.out.print(firstNumber + " " + secondNumber); 10 | while(firstNumber map = new ConcurrentHashMap(); 10 | map.put("key1", "value1"); 11 | map.put("key2", "value2"); 12 | map.put("key3", "value3"); 13 | 14 | Iterator iterator = map.keySet().iterator(); 15 | 16 | while (iterator.hasNext()) { 17 | System.out.println(map.get(iterator.next())); 18 | map.put("key4", "value4"); 19 | } 20 | 21 | } 22 | 23 | } -------------------------------------------------------------------------------- /src/main/java/com/in28minutes/java/beginners/program/examples/number/FibonacciSeriesRecursion.java: -------------------------------------------------------------------------------- 1 | package com.in28minutes.java.beginners.program.examples.number; 2 | 3 | public class FibonacciSeriesRecursion { 4 | 5 | public static void generateSeriesUpto(int limit) { 6 | int firstNumber = 0; 7 | int secondNumber = 1; 8 | System.out.print(firstNumber + " " + secondNumber); 9 | while(firstNumber