PHP preg_match to extract a certain number from a string

Question

I have a multi line string like:

$msg = "Fix #1: This is a message
Fix #2
Fix #5";

I've tried a lot of patterns but none worked the way I want it to work.

What I want preg_match to do is to return an array with 1, 2 and 5. The pattern should check for all Fix #NUM and return all the NUM in an array.

You're probably pretty close with some of your attempts. Show us what you've tried and we can go from there. — Andy Lester
– Andy Lester, Commented Feb 12, 2015 at 15:11

hwnd · Accepted Answer · 2015-02-12 15:06:22Z

1

You can use preg_match_all() and simply match digits alone to return the desired results.

preg_match_all('/\d+/', $msg, $matches);
var_dump($matches[0]);

If the matches need to be preceded by Fix #, you can use the following:

preg_match_all('/Fix\s+#\K\d+/', $msg, $matches);

This matches "Fix" followed by whitespace characters "one or more" times followed by #.

The \K escape sequence resets the starting point of the reported match and any previously consumed characters are no longer included.

answered Feb 12, 2015 at 14:47

hwnd

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2 Comments

var_dump($matches[1]) :)

This works pretty good, can you please explain the second pattern? Especially the \K

Sverri M. Olsen · Accepted Answer · 2015-02-12 14:49:37Z

1

If Fix # has to be in-front of the number then something like this should do it:

/(?<=Fix\s+#)\d+/

Otherwise this is fine:

/\d+/

answered Feb 12, 2015 at 14:49

Sverri M. Olsen

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Avinash Raj · Accepted Answer · 2015-02-12 14:47:31Z

0

You need to use preg_match_all with this \d+ regex because preg_match would return only a single match. It won't do a global match.

answered Feb 12, 2015 at 14:47

Avinash Raj

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