C-bit operation

C-bit operation
In many system programs, bit-level operations or processing are often required. The C language provides the bitwise operation function, which allows the C language to be used to write system programs like the assembly language.

The C language provides six bitwise operators:
& Bitwise AND

| By bit or

^ Bitwise OR

~ Invert

<Move left

> Right shift

12.1.1 bitwise AND OPERATION
Bitwise AND operator "&" are binary operators. Its function is the binary phase corresponding to the two numbers involved in the operation. The result bit is 1 only when the two binary numbers are 1. Otherwise, the result bit is 0. The number of involved operations is supplemented.

For example, 9 & 5 can be written as follows:

00001001 (Binary complement of 9)

& Amp; 00000101 (Binary complement of 5)

00000001 (Binary complement of 1)

Visible 9 & 5 = 1.

Bitwise AND operations are usually used to clear some bits or retain some bits. For example, if a clears the high eight bits of 0 and retains the low eight bits, it can be used as a & 255 operation (255 of the binary number is 0000000011111111 ).

[Example 12.1]

Main (){

Inta = 9, B = 5, c;

C = a & B;

Printf ("a = % dnb = % dnc = % dn", a, B, c );

}

12.1.2 bitwise OR operation
The bitwise OR operator "|" is a binary operator. Its function is the binary phase or corresponding to the two numbers involved in the operation. If one of the two binary numbers is 1, The result bit is 1. The two numbers involved in the operation appear as a complement.

For example, 9 | 5 can be written as follows:

00001001

| 00000101

00001101 (decimal 13) Visible 9 | 5 = 13

[Example 12.2]

Main (){

Inta = 9, B = 5, c;

C = a | B;

Printf ("a = % dnb = % dnc = % dn", a, B, c );

}

12.1.3 bitwise XOR operation
The bitwise XOR operator "^" is a binary operator. This function is used to calculate whether the binary numbers corresponding to the binary numbers are different or not. When the binary numbers of the two numbers are different, the result is 1. The number of involved operations still appears as a complement. For example, 9 ^ 5 can be written as follows:

00001001