(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.
num1The number to scan.
A GMP object, an int,
or a string that can be interpreted as a number following the same logic
as if the string was used in gmp_init() with automatic
base detection (i.e. when base is equal to 0).
startThe starting bit.
Returns the index of the found bit, as an int. If no set bit is found, -1 is returned.
Example #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";
?>The above example will output:
3 9