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gmp_sign> <gmp_scan1
Last updated: Fri, 04 Jul 2008

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gmp_setbit

(PHP 4 >= 4.0.4, PHP 5)

gmp_setbit — Set bit

Beschreibung

void gmp_setbit ( resource &$a , int $index [, bool $set_clear ] )

Sets bit index in a .

Parameter-Liste

a

The number being set to.

Dies kann entweder eine resource für einen GMP Wert sein oder ein numerischer String wenn es möglich ist diesen in einen GMP Wert umzuwandeln.

index

The set bit.

set_clear

Defines if the bit is set to 0 or 1. By default the bit is set to 1. Index starts at 0.

Rückgabewerte

Eine resource für einen GMP Wert.

Beispiele

Beispiel #1 gmp_setbit() example

<?php
$a 
gmp_init("0xfd");
gmp_setbit($a1); // index starts at 0
echo gmp_strval($a) . "\n";
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

255

Anmerkungen

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



add a note add a note User Contributed Notes
gmp_setbit
bluej100@gmail
27-Jul-2007 09:07
The third parameter is somewhat confusingly named; it would probably be better described as "$set_state". If true, it sets the bit to 1. If false, it sets the bit to 0. Default is true.

<?php
$num
= gmp_init(1);
gmp_setbit($num, 1);
echo
'gmp_setbit(1, 1): '.gmp_strval($num, 2)."\n"; // 11

$num = gmp_init(1);
gmp_setbit($num, 1, true);
echo
'gmp_setbit(1, 1, true): '.gmp_strval($num, 2)."\n"; // 11

$num = gmp_init(1);
gmp_setbit($num, 0, false);
echo
'gmp_setbit(1, 0, false): '.gmp_strval($num, 2)."\n"; // 0
?>

gmp_sign> <gmp_scan1
Last updated: Fri, 04 Jul 2008
 
 
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