Now Starting regular Codes Of Java
You Want To practice these Codes in Regular basis

// #3 Arrays in Java

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

int arr[] = {2, 3, 6};
//Array declaration and initialization

System.out.println(arr[0]);
//Showing Array First element

}
}

//#4 Declaring & iniitializing Array

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

int arr[]; //declaring array
arr = new int[20]; // allocating memory

arr[0]= 55; //iniitializing first element
arr[1]= 33; //initi.... 2nd Element
System.out.println(arr[0]);
}
}

// #5 Atithmetic Operations in Java

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

// declaring variables
int add, sub, div, mul, rem;

// Declaring two varables
int x=4;
int y=2;

// performing Operations
add = x+y; // Addition
sub = x-y; // Subtraction
div = x/y; // Division
mul = x+y; // Multiply
rem= x%y; // reminder

// Showing results
System.out.println("4 + 2 = "+ add);
System.out.println("4 - 2 = "+ sub);
System.out.println("4 * 2 = "+ mul);
System.out.println("4 / 2 = "+ div);
System.out.println("4 % 2 = "+ rem);
}
}

//#6 2 Number Adder(Calculator) from user input

// This for Scan anything entered by user (user inputs)
import java.util.Scanner;

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

int x,y,Sum;

Scanner s = new Scanner(System.in);
// it will take input from keyboard

System.out.println("Enter 1st Number: ");
x = s.nextInt(); // scanning

System.out.println("Enter 2nd Number: ");
y = s.nextInt(); // scanning

Sum = x+y;
System.out.println("Sum = "+ Sum);
}
}