(PHP 4 >= 4.0.4, PHP 5, PHP 7)
gmp_scan0 — Scan for 0
Scans a, starting with bit
start, towards more significant bits,
until the first clear bit is found.
aThe number to scan.
PHP 5.5 之前为 GMP 数值资源，PHP 5.6 之后为 GMP 对象或数字，或可以转为数字的字符串。
startThe starting bit.
Returns the index of the found bit, as an integer. The index starts from 0.
Example #1 gmp_scan0() example
<?php
// "0" bit is found at position 3. index starts at 0
$s1 = gmp_init("10111", 2);
echo gmp_scan0($s1, 0) . "\n";
// "0" bit is found at position 7. index starts at 5
$s2 = gmp_init("101110000", 2);
echo gmp_scan0($s2, 5) . "\n";
?>
以上例程会输出：
3 7