C language-bitwise operator, C language-Operator

C language-bitwise operator, C language-Operator
I. bitwise operators 1. bitwise AND :&

1> Functions

* The result bit is 1 only when the corresponding two binary bits are 1. Otherwise, the result bit is 0.

* Example: 10 is represented as 1010 in binary format and 7 is represented as 0111 in binary format. Calculate two values

* 1010

0111

--------------------

0010

* Rule: In the binary system, it is in the same position as the 1 phase, and the 0 phase is 0.

2> application: Use the & operator to determine the parity of an integer variable

1 int main () 2 {3 int a = 10; 4 a & 1? Printf ("% d is an odd number", a): printf ("% d is an even number", a); 5 return 0; 6}Use & to determine the parity of variables 2. bitwise OR: |

1> Functions

* If one of the two binary bits is 1, the result is 1. Otherwise, the result is 0.

2> Applications

* 10 is represented as 1010 in binary format, and 7 is represented as 0111 in binary format. Perform | operation on two values

* 1010

0111

--------------------

1111

3. bitwise OR: ^

1> Functions

* When the binary phase is different, the result is 1; otherwise, the result is 0.

* Example: 10 is represented as 1010 in binary format and 7 is represented as 111 in binary format. Perform the ^ operation on the two values

* 1010

0111

--------------------

1101

2> application: Use bitwise OR operators to swap two variable values

1 int main () 2 {3/* This usage is based on three rules. 4 1. perform an exclusive or operation for the same value, and the result is 0. 5 2. If any value excludes or with 0, the result is still the original value. 6 3. exchange Rules: a ^ B ^ c = a ^ c ^ B */7 int a = 10; 8 int B = 11; 9 a = a ^ B; // a = 10 ^ 1110 B = a ^ B; // B = 10 ^ 11 ^ 11 = 1011 a = a ^ B; // a = 10 ^ 11 ^ 10 = 1112 printf ("a = % d, B = % d", a, B); 13}Exchange Value

 

4. bitwise inversion :~

1> Functions

* Bitwise inversion is used to perform an inverse operation on each binary bit of a value. If the value is 0, the value is reversed to 1, and the value is reversed to 0.

2> Applications

* Example: 10 is represented as 1010 in binary format ~ Operation

* 1010

--------------------

0101

5. Shift left <, shift right>

1> Functions

* A <n indicates that each binary Bit Of a is moved to the left n bits, and the position is discarded at the top. The position is supplemented by 0 and the left n bits are actually multiplied by the n power of 2; a> n is to move the binary bits of a to the right n bits, to keep the symbol bit unchanged and to the right n bits. In fact, it is divided by the Npower of 2.

2> Applications

* Example: 10 is represented as 1010 in binary format, and 1010 is shifted to 1 bit. The result is 10100, that is, 20. 1010 is shifted to 1 bit. The result is 101, that is, 5.

* Note: When you perform multiplication or division on variables in the future, you can use shift left or shift right to improve the performance.