regex declare a 'default value' if a tag is empty

Question

I have a regular expression which is it returns anything inside the html tag with id="test"

ex:

<span id="test">Hello World</span>

 <.*?id="pStyle".*?>(.*?)</.*?>

it returns Hello World

what if a tag is empty it should return too like

<span id="test"></span>

it should return a default value if a tag is empty. I'm currently new on regex is there any regular expression to derrive this empty tags?

http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags/1732454#1732454 — pobrelkey, Nov 16 '13 at 08:24

score 0 · Answer 1 · edited Nov 16 '13 at 08:32

0

Maybe after any symbols <.*?id="pStyle".*?>(.*?)</.*?> You should add more than one symbol

<(.*)id="pStyle"(.*)>(.*)<\/ (.*)>

For me it worked fine

edited Nov 16 '13 at 08:32

falsetru

357,413
63
732
636

answered Nov 16 '13 at 08:21

Farhad

742
6
22

score 0 · Accepted Answer · answered Nov 16 '13 at 08:26

0

I assume that you use preg_match function. It will always return a string when there is a match. If you want to return null if the tag is empty I think you should add an if statement, e.g.

$string = '<span id="test">Hello World</span>';
$matches = array();
if (preg_match('%<.*?id="pStyle".*?>(.*?)</.*?>%', $string, $matches) {
    if (empty($matches[1])) {
        return null;
    }
    return $matches[1];
}

Also I'd suggest not using this structure: .*?. If I would write this RegEx, I would do it that way:

<[^>]*id="pStyle"[^>]*>([^<]*)</[^>]*>

[^>]* means: Zero or more characters other than >.

answered Nov 16 '13 at 08:26

matewka

9,912
2
32
43

i come up with this it wont do anything ` $value = 'A'; $match = array(); if(preg_match('%<[^>]*id="test2"[^>]*>([^<]*)[^>]*>%', $html, $match)) { $html = str_replace($match[1],$value,$html); }` – Darline Nov 16 '13 at 08:36
@Darline is your goal to replace the text inside the tag with the `A` string? – matewka Nov 16 '13 at 10:50

regex declare a 'default value' if a tag is empty

2 Answers2