How to find this regex using PHP

Question

find all the <1></1> and <2></2> and <3></3>... in a string.

Before you go too far down this road, please read this question: http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags — Greg Hewgill, Dec 08 '09 at 10:18

Joey · Accepted Answer · 2009-12-08T10:17:42.747

2

<(\d+)></\1>

should work. This ensures that the regex won't match <1></4> for example.

\1 is here a backreference which must match exactly the same string as the first capturing group (the (\d+) in the first angle brackets).

edited Dec 08 '09 at 10:17

answered Dec 08 '09 at 10:11

Joey

2

Should I? I don't know. But I did. By the way, http://www.regular-expressions.info/ is a great site to learn. – Joey Dec 08 '09 at 10:18

score 1 · Answer 2 · answered Dec 08 '09 at 10:11

1

One regex to match any of them?

<([1-3])></\1>

Should there code allow for anything to be posted in between the > and the <? Something like this then:

<([1-3])>(.*?)</\1>

answered Dec 08 '09 at 10:11

David Hedlund

BitDrink · Answer 3 · 2009-12-08T10:34:10.827

0

You can use the following regex: <[0-9]></[0-9]>

EDIT: To avoid that the search matches <2></3> too, you can use a sub-expression and a backreference to instantiate it: <([0-9])></\1>

edited Dec 08 '09 at 10:34

answered Dec 08 '09 at 10:11

BitDrink

score 0 · Answer 4 · answered Dec 08 '09 at 10:15

0

<STYLE[^>]*>([\s\S]*?)<\/STYLE[^>]*>

Just replace STYLE with your tag like 1, 2 whatever.

answered Dec 08 '09 at 10:15

Sarfraz

4 Answers4