gmp_clrbit

Clear bit

&reftitle.description; `void` `gmp_clrbit` `resource` `a` `int` `index`

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

&reftitle.parameters;

`a`

- &gmp.parameter;

`index`

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

&reftitle.returnvalues;

&gmp.return;

&reftitle.examples;

### `gmp_clrbit` example

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

&example.outputs;

    254

&reftitle.notes;

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

&reftitle.seealso;

- `gmp_setbit`
- `gmp_testbit`