Bitwise operators in Java

Bitwise operators are used to perform manipulation of individual bits of a number. They can be used with any of the integral types (char, short, int, etc). They are used when performing update and query operations of Binary indexed tree.

Bitwise OR (|) –
This operator is binary operator, denoted by ‘|’. It returns bit by bit OR of input values, i.e, if either of the bits is 1, it gives 1, else it gives 0.
For example,
```
a = 5 = 0101 (In Binary)
b = 7 = 00011001 (In Binary)

Bitwise OR Operation of 5 and 7
  0101
| 0111
 ________
  0111  = 7 (In decimal) 
```
Bitwise AND (&) –
This operator is binary operator, denoted by ‘&’. It returns bit by bit AND of input values, i.e, if both bits are 1, it gives 1, else it gives 0.
For example,
```
a = 5 = 0101 (In Binary)
b = 7 = 00011001 (In Binary)

Bitwise AND Operation of 5 and 7
  0101
& 0111
 ________
  0101  = 5 (In decimal) 
```
Bitwise XOR (^) –
This operator is binary operator, denoted by ‘^’. It returns bit by bit XOR of input values, i.e, if corresponding bits are different, it gives 1, else it gives 0.
For example,
```
a = 5 = 0101 (In Binary)
b = 7 = 00011001 (In Binary)

Bitwise XOR Operation of 5 and 7
  0101
^ 0111
 ________
  0010  = 2 (In decimal) 
```
Bitwise Complement (~) –
This operator is unary operator, denoted by ‘~’. It returns the one’s compliment representation of the input value, i.e, with all bits inversed, means it makes every 0 to 1, and every 1 to 0.
For example,
```
a = 5 = 0101 (In Binary)
b = 7 = 00011001 (In Binary)

Bitwise Compliment Operation of 5 and 7

~ 0101
 ________
  1010  = 10 (In decimal) 
```
Note – Compiler will give 2’s complement of that number, i.e., 2’s compliment of 10 will be -6.

// Java program to illustrate 
// bitwise operators 
public class operators { 
    public static void main(String[] args) 
    { 
        //hexadecimal representation  
        int a = 0x0005; 
        int b = 0x0007; 
  
        // bitwise and 
        // 0101 & 0111=0101 = 5 
        System.out.println("a&b = " + (a & b)); 
  
        // bitwise or 
        // 0101 | 0111=0111 = 7 
        System.out.println("a|b = " + (a | b)); 
  
        // bitwise xor 
        // 0101 ^ 0111=0010 = 2 
        System.out.println("a^b = " + (a ^ b)); 
  
        // bitwise and 
        // ~0101=1010 
        // will give 2's complement of 1010 = -6 
        System.out.println("~a = " + ~a); 
  
        // can also be combined with 
        // assignment operator to provide shorthand 
        // assignment 
        // a=a&b 
        a &= b; 
        System.out.println("a= " + a); 
    } 
} 

Output :

a&b = 5
a|b = 7
a^b = 2
~a = -6
a= 5

Shift Operators: These operators are used to shift the bits of a number left or right thereby multiplying or dividing the number by two respectively. They can be used when we have to multiply or divide a number by two. General format:

 number shift_op number_of_places_to_shift;

Left shift operator (<<) –
Shifts the bits of the number to the left and fills 0 on voids left as a result. Similar effect as of multiplying the number with some power of two.
For example,
```
a = 5 = 0000 0101
b = -10 = 1111 1010

a << 1 = 0000 1010 = 10
a << 2 = 0001 0100 = 20 
```
Unsigned Left shift operator (<<<) -
There is no "<<<" operator in Java, because the logical (<<) and arithmetic left-shift (<<<) operations are identical.
Signed Right shift operator (>>) -
Shifts the bits of the number to the right and fills 0 on voids left as a result. The leftmost bit depends on the sign of initial number. Similar effect as of dividing the number with some power of two.
For example,
```
a = 5 = 0000 0101
b = 10 = 0000 1010 (takes 2's compliment)
b = -10 = 1111 0110

b >> 1 = 1111 1011 
b >> 2 = 1111 1101 (takes 2's compliment) = -3 
```
Unsigned Right shift operator (>>>) -
Shifts the bits of the number to the right and fills 0 on voids left as a result. The leftmost bit is set to 0. (>>>) is unsigned-shift; it'll insert 0. (>>) is signed, and will extend the sign bit.
For example,
```
a = 5 = 0000 0101
b = 10 = 0000 1010 (takes 2's compliment)
b = -10 = 1111 0110

b >> 1 = 1
b >> 2 = (takes 2's compliment) = 1073741821 
```

// Java program to illustrate 
// shift operators 
public class operators { 
    public static void main(String[] args) 
    { 
  
        int a = 0x0005; 
        int b = -10; 
  
        // left shift operator 
        // 0000 0101<<2 =0001 0100(20) 
        // similar to 5*(2^2) 
        System.out.println("a<<2 = " + (a << 2)); 
  
        // right shift operator 
        // 0000 0101 >> 2 =0000 0001(1) 
        // similar to 5/(2^2) 
        System.out.println("b>>2 = " + (b >> 2)); 
  
        // unsigned right shift operator 
        System.out.println("b>>>2 = " + (b >>> 2)); 
    } 
} 

Output :

a<<2 = 20
b>>2 = -3
b>>>2 = 1073741821

Refer for - other Operators in Java

My Personal Notes

Recommended Posts: