Java Tutorial - Java Bitwise Operators

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Bitwise Operators act upon the individual bits of their operands. Java bitwise operators can be applied to the integer types: long, int, short, char, byte.

Bitwise operators List

The following table lists all Java bitwise operators.

Operator	Result
~	Bitwise unary NOT
&	Bitwise AND
|	Bitwise OR
^	Bitwise exclusive OR
>>	Shift right
>>>	Shift right zero fill
<<	Shift left
&=	Bitwise AND assignment
|=	Bitwise OR assignment
^=	Bitwise exclusive OR assignment
>>=	Shift right assignment
>>>=	Shift right zero fill assignment
<<=	Shift left assignment

Bitwise operator assignments combines the assignment with the bitwise operation. The following two statements are equivalent:

a = a >> 4; 
a >>= 4;  

The following two statements are equivalent:

a = a | b; 
a |= b;

The following program demonstrates the bitwise operator assignments:

 
public class Main {
  public static void main(String args[]) {
    int a = 1;/*from   ww w  .j a va  2 s.co  m*/
    int b = 2;
    int c = 3;
    a |= 2;
    b >>= 2;
    c <<= 2;
    a ^= c;
    System.out.println("a = " + a);
    System.out.println("b = " + b);
    System.out.println("c = " + c);

  }
}

The output of this program is shown here:

Java Left Shift Operator

The left shift operator, <<, shifts all of the bits in a value to the left a specified number of times.

It has this general form:

value << num

The following code shifts byte type variable.

 
public class Main {
  public static void main(String args[]) {
    byte a = 64, b;
    int i;/*from   ww  w.j a v a 2 s .c  o  m*/
    i = a << 2;
    b = (byte) (a << 2);
    System.out.println("Original value of a: " + a);
    System.out.println("i and b: " + i + " " + b);
  }
}

The output generated by this program is shown here:

Example

Each left shift has the effect of doubling the original value. The following program illustrates this point:

 
public class Main {
  public static void main(String args[]) {
    int num = 0xFFFFFFF;
// ww  w  .j  a va 2 s.  com
    for (int i = 0; i < 4; i++) {
      num = num << 1;
      System.out.println(num);

    }
  }
}

The program generates the following output:

Java Right Shift Operator

The right shift operator, >>, shifts all of the bits in a value to the right a specified number of times.

Its general form is shown here:

value >> num

num specifies the number of positions to right-shift.

The following code fragment shifts the value 32 to the right by two positions:

 
public class Main {
  public static void main(String[] argv) {

    int a = 32;
    a = a >> 2;
    System.out.println("a is " + a);

  }
}

The output:

Java Unsigned Right Shift

Java's unsigned, shift-right operator, >>>, always shifts zeros into the high-order bit.

Its general form is shown here:

value >>> num

num specifies the number of positions to right-shift.

The following code shows how to use unsigned right shift.

public class Main {
  public static void main(String[] argv) {
    int a = -1;
    a = a >>> 24;

    System.out.println("a is " + a);
  }
}

The output:

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