PHP preg_replace with logic?

Question

What if I want to multiply all numbers by 2? Can this be done with regex replace? Note the $1*2 part that obviously doesn't work. How would I do this?

$foo = "soup 12 cake 23 pants";
$bar = preg_replace('~(\d+)~', $1*2, $foo);

Variable names can't be numbers.

Leri
– Leri

2012-08-13 18:05:21 +00:00
Commented Aug 13, 2012 at 18:05 — Leri
– Leri, Commented Aug 13, 2012 at 18:05
You could use preg_replace_callback

knittl
– knittl

2012-08-13 18:05:51 +00:00
Commented Aug 13, 2012 at 18:05 — knittl
– knittl, Commented Aug 13, 2012 at 18:05
@PLB Yea, that's cute. Read the question.

Farzher
– Farzher

2012-08-13 18:06:20 +00:00
Commented Aug 13, 2012 at 18:06 — Farzher
– Farzher, Commented Aug 13, 2012 at 18:06
@knittl preg_replace_callback is what I needed. Thanks!

Farzher
– Farzher

2012-08-13 18:07:33 +00:00
Commented Aug 13, 2012 at 18:07 — Farzher
– Farzher, Commented Aug 13, 2012 at 18:07

Farzher · Accepted Answer · 2012-08-13 18:28:26Z

3

You could use preg_replace_callback:

preg_replace_callback('~(\d%)~', function($match) { return $match[1]*2; }, $foo);

edited Aug 13, 2012 at 18:28

Farzher

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answered Aug 13, 2012 at 18:07

knittl

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Comments

jlx84 · Accepted Answer · 2012-08-13 18:08:13Z

2

try using the preg_replace_callback(...) function

<?php

function mulBy2($match) {
    return $match[1] * 2;
}

$foo = "soup 12 cake 23 pants";
$bar = preg_replace_callback('~(\d+)~', "mulBy2", $foo);

echo $bar;

?>

answered Aug 13, 2012 at 18:08

jlx84

1011 silver badge4 bronze badges

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