Java Integer rotateLeft() Method

The rotateLeft() method of Java Integer class returns the value obtained by rotating the two's complement binary representation of the specified int value left by the specified number of bits. (Bits shifted out of the left hand, or high-order).

Bit shifting is a bitwise operation which is performed on all the bits of a binary value by moving the bits to a definite number of places towards left or right.

Java has a single Logical left shift operator (<<).

Explanation:

Suppose, rotateLeft(10,2) 
Value = 10
Equivalent Binary Value = 00001010 
Shifted 1-bit left = 00010100 i.e. Becomes -> 20
Shifted 2-bit left = 00101000 i.e. Becomes -> 40

Syntax:

Following is the declaration of rotateLeft () method:

Parameter:

DataType	Parameter	Description	Required/Optional
int	i	Numeric value entered by a user whose bits are to be rotated left	Required
int	distance	Number of bit positions (distance) to rotate left which is entered by a user.	equired

Returns:

The rotateLeft () method returns the value obtained by rotating the two's complement binary representation of the specified int value left by the specified number of bits.

Exceptions:

Compatibility Version:

Java 1.5 and above

Example 1

public class IntegerRotateLeftExample1 {
	public static void main(String[] args) {
		System.out.println(Integer.rotateLeft(10,2));	  
	}
}

Output:

Example 2

public class IntegerRotateLeftExample2 {
	public static void main(String[] args) {
		int value = 16;
		// Get the binary equivalent
		System.out.println("Binary equivalent: "+Integer.toBinaryString(value));
		// get the  number of one's
		int Result = Integer.rotateLeft(value, 3);
		System.out.println("Value after left rotation: "+Result);
		System.out.println("New Binary value after Rotated Left: "+Integer.toBinaryString(Result));	  
	}
}

Output:

Binary equivalent: 10000
Value after left rotation: 128
New Binary value after Rotated Left: 10000000

Example 3

import java.util.Scanner;
public class IntegerRotateLeftExample3 {
	public static void main(String[] args)
    {
	  System.out.print("Enter the Number: ");
	  Scanner sc = new Scanner (System.in);
        int a = sc.nextInt();
        int shifts = 0;
        while (shifts < 3)
        // It will return the value obtained by left rotation
        {        	
            a = Integer.rotateLeft(a, shifts);
            System.out.println("Value: "+a);
            System.out.println("Binary equivalent: "+Integer.toBinaryString(a)); 
            shifts++;
        }        
    }
}			

Output:

Enter the Number: 16
Value: 16
Binary equivalent: 10000
Value: 32
Binary equivalent: 100000
Value: 128
Binary equivalent: 10000000

Example 4

public class IntegerRotateLeftExample4 {
	public static void main(String[] args) {
		int a = -12;
            int shifts = 0;
            while (shifts < 3)
            // It will return the value obtained by left rotation
            {
            a = Integer.rotateLeft(a, shifts);
            System.out.println("Value: "+a);
            shifts++;
            }
      }
}

Output: