To declare a whole number in java, use int as the keyword. We should assign the name and volume to the int. That assigning called initialization.

package variables.Variables;

public class IntSample {

    public static void main(String[] args) {
	// write your code here

        int a = 4;
        int b = 3;

        System.out.println(a+b);
        System.out.println(a-b);
        System.out.println(a*b);
        System.out.println(a/b);

        long c = 2147483648L;

        System.out.println(c);
    }
}

The int can store 32 bits. From (-2 ^ 31) to (2 ^ 31) - 1

The int can’t store long numbers. At that time you need long as the keyword. You should type L after the number.

long can store 64 bits. From (-2 ^ 63) to (2 ^ 63) - 1

There are another two types in integer to store small numbers. Those keywords are bit and short.

bit can store 8 bits. From (-2 ^ 7) to (2 ^ 7) - 1

short can store 16 bits. From (-2 ^ 15) to (2 ^ 15) -1