gmp_scan1

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

gmp_scan1 — Scan for 1

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gmp_scan1 ( GMP $a , int $start ) : int

Scans a, starting with bit start, towards more significant bits, until the first set bit is found.

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a

The number to scan.

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start

The starting bit.

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Returns the index of the found bit, as an integer. If no set bit is found, -1 is returned.

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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";
?>

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3
9