Kaushal28

class Test {
    int instanceVar = 10;

    void hideInstance() {
        int instanceVar = 15;
        System.out.println("Local variable: " + instanceVar); //This will print local variable, as instance variable is hidden
        //To access instance variable here, use this.instanceVariable
        System.out.println("Instance variable: " + this.instanceVar);
    }
}

Kaushal28

import java.io.FileNotFoundException;

/**
 * Most common checked and unchecked exceptions
 * https://stackoverflow.com/questions/1263128/most-common-checked-and-unchecked-java-exceptions
 */

class ExceptionExample {
    //This is throwing (possibility of throwing) checked exception
    void sampleMethod() throws FileNotFoundException {

Kaushal28

/**
 * Rule #1:
 * If the super-class overridden method does not throw an exception, 
 * subclass overriding method can only throws the unchecked exception, 
 * throwing checked exception will lead to compile-time error.
 * 
 * Rule #2:
 * If the super-class overridden method does throws an exception, subclass 
 * overriding method can only throw same, subclass exception. Throwing parent 
 * exception in Exception hierarchy will lead to compile time error. Also there 

Kaushal28

interface one {
    public void printOne();
}

interface two {
    public void printTwo();
}

interface three extends one, two{
    public void printThree();

Kaushal28

class Car {
    int number;

    Car(int number) {
        this.number = number;
    }

    void printNumber() {
        System.out.println(this.number);
    }

Kaushal28

public class LabelsExample {
    public static void main (String[] args) {

        //Labels with break; Similar functionality like goto
        outerLoop:
        for (int i=0;i<10;i++) {
            for (int j=0;j<10;j++) {
                if (j == 1) {
                    System.out.println(j);
                    break outerLoop;

Kaushal28

class TestFinalVariable {
    public final int foo;
    // If variable is static and final, it must be initialized right away.
    public static final int bar = 10;

    //In constructor, initialization of final variable is allowed, as compiler knows that the constructor can only be called 1 time per object.
    //Static variables can not be initialized even in constructor, as they are shared between multiple objects and that's why multiple object
    //initialization can updathe the same copy of final variable, which is not allowed and thus static final variable must be initialized on declaration
    TestFinalVariable(int foo) {
        this.foo = foo;

Kaushal28

import java.util.EnumSet;
import java.util.EnumMap;

enum Directions {

    // Abstract method needs to be overriden in each of the enums
    // First line of Enum should be always enum declaration. Constructor, variables declaration not allowed.
    EAST(0) {
        @Override
        public void printDirection() {

Kaushal28

class ShutDownHookExample {
    public static void main(String[] args) {
        Runtime.getRuntime().addShutdownHook(new Thread() {
            public void run() {
                System.out.println("Shutdown hook is running.");
            }
        });
        System.out.println("Application terminating.");
    }
}

Kaushal28

import numpy as np
T = np.load('datasets/T.npy')
for i in range(12):
    for j in range(4):
        print (T[i,:,j])
        
'''
[0.9 0.1 0.  0.  0.  0.  0.  0.  0.  0.  0.  0. ]  for starting state (1,1) and action Down
[0.9 0.  0.  0.  0.1 0.  0.  0.  0.  0.  0.  0. ]  for starting state (1,1) and action Left 
[0.1 0.1 0.  0.  0.8 0.  0.  0.  0.  0.  0.  0. ]  for starting state (1,1) and action Up