gmp_com()
(PHP 4 >= 4.0.4, PHP 5, PHP 7)
Calculates one's complement
说明
gmp_com(GMP$a): GMP
Returns the one's complement of$a.
参数
- $a
可以是一个 GMP数据resouce,或一个可以转换为数值的字符串。
返回值
Returns the one's complement of$a, as a GMP number.
范例
gmp_com() example
<?php $com = gmp_com("1234"); echo gmp_strval($com) . "\n"; ?>
以上例程会输出:
-1235
If you're using one's compliment (bitwise NOT) to flip all $a's bits, don't forget that you need to use a mask to specify how many bits you expect in your result: <?php gmp_and(gmp_com('1234'), '2047') ?> >> 813 // 01100101101 in binary I chose 2047 because 1234 is an 11-bit binary number and 2047 is the maximum an 11-bit register can hold: 11111111111 (2047) 10011010010 (1234) 01100101101 (813)