位运算就是直接对整数在内存中的二进制位进行操作,按位运算符对位进行操作,并执行逐位运算。
&,|和^的真值表如下:
假设A = 60,B = 13,二进制格式如下:
A = 0011 1100
B = 0000 1101
A&B = 0000 1100
A|B = 0011 1101
A^B = 0011 0001
~A = 1100 0011
下表列是C语言支持的按位运算符。假设变量A=60,变量B=13
创建源代码文件:mbitwise_operators.c,代码如下所示:
#include <stdio.h>
main() {
unsigned int a = 60; /* 60 = 0011 1100 */
unsigned int b = 13; /* 13 = 0000 1101 */
int c = 0;
c = a & b; /* 12 = 0000 1100 */
printf("Line 1 - Value of c is %d\n", c );
c = a | b; /* 61 = 0011 1101 */
printf("Line 2 - Value of c is %d\n", c );
c = a ^ b; /* 49 = 0011 0001 */
printf("Line 3 - Value of c is %d\n", c );
c = ~a; /*-61 = 1100 0011 */
printf("Line 4 - Value of c is %d\n", c );
c = a << 2; /* 240 = 1111 0000 */
printf("Line 5 - Value of c is %d\n", c );
c = a >> 2; /* 15 = 0000 1111 */
printf("Line 6 - Value of c is %d\n", c );
}
执行代码,得到如下结果:
Line 1 - Value of c is 12
Line 2 - Value of c is 61
Line 3 - Value of c is 49
Line 4 - Value of c is -61
Line 5 - Value of c is 240
Line 6 - Value of c is 15
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