preg_replace - strip unwanted characters from string to return numeric value

Question

I hate regular expressions and I was hoping someone could help with a regualar expression to be used with preg_replace.

I want to strip unwanted characers from a string to return just a numeric value using preg_replace.

The string format could be as follows:

SOME TEXT £100

£100 SOME TEXT

SOME TEXT 100 SOME TEXT

Many thanks

So all these yield 100, right? What happens to 1abc00?

BoltClock
– BoltClock

2011-01-09 13:48:03 +00:00
Commented Jan 9, 2011 at 13:48 — BoltClock
– BoltClock, Commented Jan 9, 2011 at 13:48
Better yet - what about £1.00?

Kobi
– Kobi

2011-01-09 13:52:30 +00:00
Commented Jan 9, 2011 at 13:52 — Kobi
– Kobi, Commented Jan 9, 2011 at 13:52

Patrick Evans · Accepted Answer · 2013-08-28 22:29:51Z

17

$NumericVal = preg_replace("/[^0-9]/","",$TextVariable);

the ^ inside the [ ] means anything except the following

Edit removed superfluous +

edited Aug 28, 2013 at 22:29

answered Jan 9, 2011 at 13:49

Patrick Evans

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2 Comments

nicorellius Over a year ago

why not use \D out of curiosity... ? many answers on web use non-number rather than the built-in "not digit"

Patrick Evans Over a year ago

@nicorellius I wrote this real quick when I answered so didn't really think to use it is all, and haven't thought of it since to edit it to use \d. Though it is more readable for people without a good knowledge of the different regex options.

user956584 · Accepted Answer · 2012-06-25 17:46:45Z

8

$l = preg_replace("/[^A-Z0-9a-z\w ]/u", '', $l);

Works witch UTF-8, allow only A-Z a-z 0-9 łwóc... etc

answered Jun 25, 2012 at 17:46

user956584

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Comments

AndreKR · Accepted Answer · 2011-01-09 13:49:21Z

0

preg_replace('/[^0-9]/','',$text);

answered Jan 9, 2011 at 13:49

AndreKR

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4 Comments

AndreKR Over a year ago

This gives 100 for Boltclock's example, too.

Patrick Evans Over a year ago

you need the + otherwise it will only replace the first non-number

AndreKR Over a year ago

No, that is partially true for preg_match but not for preg_replace. Just like any normal replace preg_replace replaces each occurence of a character that is [^0-9] with nothing and then continues its search with the next character.

Kobi Over a year ago

@Patrick - if that was the case, it would fail on acb100def - the solution would be the /g flag. That's true for JavaScript, but not in PHP.

Kobi · Accepted Answer · 2011-01-09 13:49:27Z

0

Try this:

preg_replace("/\D+/", "", "SOME TEXT £100")

You can also use preg_match to get the first number:

preg_match("/\d+/", "SOME TEXT £100", $matches);
$number = $matches[0];

answered Jan 9, 2011 at 13:49

Kobi

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1 Comment

MarcoZen Over a year ago

Note that \D is the same as [^\d]

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