(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.
Throws a ValueError if start is negative or, as of PHP 8.5.0, too large.
Prior to PHP 8.0.0, an E_WARNING was raised instead.
Приклад #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";
?>Поданий вище приклад виведе:
3 9