(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)
gmp_scan1 — Scan for 1
Scans num1
, starting with bit
start
, towards more significant bits,
until the first set bit is found.
Returns the index of the found bit, as an int. If no set bit is found, -1 is returned.
示例 #1 gmp_scan1() example
<?php
// "1" bit is found at position 3. index starts at 0
$s1 = gmp_init("01000", 2);
echo gmp_scan1($s1, 0) . "\n";
// "1" bit is found at position 9. index starts at 5
$s2 = gmp_init("01000001111", 2);
echo gmp_scan1($s2, 5) . "\n";
?>
以上示例会输出:
3 9