Java Bitwise and Bit Shift Operators

Java provides 4 bitwise and 3 bit shift operators to perform bit operations. You will learn about them in detail in this article.

Bitwise and bit shift operators are used on integral types (byte, short, int and long) to perform bit-level operations.

These operators are not commonly used. You will learn about a few use cases of bitwise operators in Java enum type chapter. This article will only focus on how these operators work.

There are 7 operators to perform bit-level operations in Java ( 4 bitwise and 3 bit shift).

Java Bitwise and Bit Shift Operators
Operator Description
| Bitwise OR
& Bitwise AND
~ Bitwise Complement
^ Bitwise XOR
<< Left Shift
>> Right Shift
>>> Unsigned Right Shift

Bitwise OR

Bitwise OR is a binary operator (operates on two operands). It's denoted by |.

The | operator compares corresponding bits of two operands. If either of the bits is 1, it gives 1. If not, it gives 0. For example,

12 = 00001100 (In Binary)
25 = 00011001 (In Binary)

Bitwise OR Operation of 12 and 25
  00001100
| 00011001
  ________
  00011101  = 29 (In decimal)

Example 1: Bitwise OR

class BitwiseOR {
    public static void main(String[] args) {
    	
    	int number1 = 12, number2 = 25, result;
    	
    	result = number1 | number2;
    	System.out.println(result);
    }
}

When you run the program, the output will be:

29

Bitwise AND

Bitwise AND is a binary operator (operates on two operands). It's denoted by &.

The & operator compares corresponding bits of two operands. If both bits are 1, it gives 1. If either of the bits is not 1, it gives 0. For example,

12 = 00001100 (In Binary)
25 = 00011001 (In Binary)

Bit Operation of 12 and 25
  00001100
& 00011001
  ________
  00001000  = 8 (In decimal)

Example 2: Bitwise AND

class BitwiseAND {
    public static void main(String[] args) {
    	
    	int number1 = 12, number2 = 25, result;
    	
    	result = number1 & number2;
    	System.out.println(result);
    }
}

When you run the program, the output will be:

8

Bitwise Complement

Bitwise complement is an unary operator (works on only one operand). It is denoted by ~.

The ~ operator inverts the bit pattern. It makes every 0 to 1, and every 1 to 0.

35 = 00100011 (In Binary)

Bitwise complement Operation of 35
~ 00100011 
  ________
  11011100  = 220 (In decimal)

Example 3: Bitwise Complement

class Complement {
    public static void main(String[] args) {
    	
    	int number = 35, result;
    	
    	result = ~number;
    	System.out.println(result);
    }
}

When you run the program, the output will be:

-36

Why are we getting output -36 instead of 220?

It's because the compiler is showing 2's complement of that number; negative notation of the binary number. 

For any integer n, 2's complement of n will be -(n+1).

 Decimal         Binary                      2's complement
---------       ---------          ---------------------------------------  
0             00000000          -(11111111+1) = -00000000 = -0(decimal)
1             00000001          -(11111110+1) = -11111111 = -256(decimal)
12            00001100          -(11110011+1) = -11110100 = -244(decimal)
220           11011100          -(00100011+1) = -00100100 = -36(decimal)

Note: Overflow is ignored while computing 2's complement.

The bitwise complement of 35 is 220 (in decimal). The 2's complement of 220 is -36. Hence, the output is -36 instead of 220.


Bitwise XOR

Bitwise XOR is a binary operator (operates on two operands). It's denoted by ^.

The ^ operator compares corresponding bits of two operands. If corresponding bits are different, it gives 1. If corresponding bits are same, it gives 0. For example,

12 = 00001100 (In Binary)
25 = 00011001 (In Binary)

Bitwise XOR Operation of 12 and 25
  00001100
| 00011001
  ________
  00010101  = 21 (In decimal)

Example 4: Bitwise XOR

class Xor {
    public static void main(String[] args) {
    	
    	int number1 = 12, number2 = 25, result;
    	
    	result = number1 ^ number2;
    	System.out.println(result);
    }
}

When you run the program, the output will be:

21

Signed Left Shift

The left shift operator << shifts a bit pattern to the left by certain number of specified bits, and zero bits are shifted into the low-order positions.

212 (In binary: 11010100)

212 << 1 evaluates to 424 (In binary: 110101000)
212 << 0 evaluates to 212 (In binary: 11010100)
212 << 4 evaluates to 3392 (In binary: 110101000000)

Example 5: Signed Left Shift

class LeftShift {
    public static void main(String[] args) {
    	
    	int number = 212, result;
    	
    	System.out.println(number << 1);
    	System.out.println(number << 0);
    	System.out.println(number << 4);
    }
}

When you run the program, the output will be:

424
212
3392

Signed Right Shift

The right shift operator >> shifts a bit pattern to the right by certain number of specified bits.

212 (In binary: 11010100)

212 >> 1 evaluates to 106 (In binary: 01101010)
212 >> 0 evaluates to 212 (In binary: 11010100)
212 >> 8 evaluates to 0 (In binary: 00000000)

If the number is a 2's complement signed number, the sign bit is shifted into the high-order positions.


Example 6: Signed Right Shift

class RightShift {
    public static void main(String[] args) {
    	
    	int number = 212, result;
    	
    	System.out.println(number >> 1);
    	System.out.println(number >> 0);
    	System.out.println(number >> 8);
    }
}

When you run the program, the output will be:

106
212
0

Unsigned Right Shift

The unsigned right shift operator >>> shifts zero into the leftmost position.


Example 7: Signed and UnSigned Right Shift

class RightShift {
    public static void main(String[] args) {
    	
    	int number1 = 5, number2 = -5;
    	
    	// Signed right shift 
    	System.out.println(number1 >> 1);
    	
    	// Unsigned right shift
    	System.out.println(number1 >>> 1);
    	
    	// Signed right shift 
    	System.out.println(number2 >> 1);
    	
    	// Unsigned right shift
    	System.out.println(number2 >>> 1);
    }
}

When you run the program, the output will be:

2
2
-3
2147483645

Notice, how signed and unsigned right shift works differently for 2's complement.

The 2's complement of 2147483645 is 3.