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<gmp_binomialgmp_cmp>
^GMP FunctionsLast updated: Mon, 26 Oct 2026

gmp_clrbit

(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

gmp_clrbit — Clear bit

Description

function gmp_clrbit(GMP $num, int $index): void

Clears (sets to 0) bit index in num. The index starts at 0.

Parameters

num

A GMP object.

index

The index of the bit to clear. Index 0 represents the least significant bit.

Return Values

No value is returned.

Errors/Exceptions

Throws a ValueError if index is negative or, as of PHP 8.5.0, too large.

Prior to PHP 8.0.0, an E_WARNING was raised instead.

Examples

Example #1 gmp_clrbit() example

<?php
$a = gmp_init("0xff");
gmp_clrbit($a, 0); // index starts at 0, least significant bit
echo gmp_strval($a) . "\n";
?>

The above example will output:

254

Notes

Note:

Unlike most of the other GMP functions, gmp_clrbit() must be called with a GMP object that already exists (using gmp_init() for example). One will not be automatically created.

See Also


<gmp_binomialgmp_cmp>
^GMP FunctionsLast updated: Mon, 26 Oct 2026