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)