int bit operations

In this chapter you will learn:

How to reverse and rotate the integer in binary format
How to bit oriented operation on int type value
How to get the leading and trailing zeros

Reverse and rotate the integer in binary format

static int reverse(int i) reverses the bits.
static int reverseBytes(int i) reverses the bytes.
static int rotateLeft(int i, int distance) rotates the bits by distance to left.
static int rotateRight(int i, int distance) rotates the bits by distance to right.

The following code reverse decimal value 10 in binary format.

public class Main {
  public static void main(String[] args) {
/*  j a  va 2  s  . c om*/
    System.out.println(Integer.reverse(10));

  }
}

The output:

The following code rotates value 10 to left for distance of 2.

public class Main {
  public static void main(String[] args) {
//  j a  v  a  2s . c o  m
    System.out.println(Integer.rotateLeft(10,2));

  }
}

The output:

Bit oriented operation

static int bitCount(int i) counts the bits
static int highestOneBit(int i) returns an int value with at most a single one-bit, in the position of the highest-order ("leftmost") one-bit.
static int lowestOneBit(int i) returns an int value with at most a single one-bit, in the position of the lowest-order ("rightmost") one-bit.

The following code does the bit oriented operation on value 10.

public class Main {
  public static void main(String[] args) {
//from   j a  va 2  s .  c o m
    System.out.println(Integer.bitCount(10));
    System.out.println(Integer.highestOneBit(10));
    System.out.println(Integer.lowestOneBit(10));
  }
}

The output:

Get the leading and trailing zeros

static int numberOfLeadingZeros(int i) returns the number of zero bits preceding the highest-order ("leftmost") one-bit
static int numberOfTrailingZeros(int i) returns the number of zero bits following the lowest-order ("rightmost") one-bit

public class Main {
  public static void main(String[] args) {
//from   j  a v a  2 s .  co  m
    System.out.println(Integer.numberOfLeadingZeros(10));
  }
}