Catching ids and its values from a string with preg_match

Question

I was wondering how can I create preg_match for catching:

id=4

4 being any number and how can I search for the above example in a string?

If this is could be correct /^id=[0-9]/, the reason why I'm asking is because I'm not really good with preg_match.

`preg_match('/^id=(\d+)/', $yourString, $matches); var_dump($matches[1]);` — Leri, Oct 31 '13 at 07:19
it's already clear, my connection was too slow to digest other comment — xnome, Oct 31 '13 at 07:28

score 2 · Accepted Answer · answered Oct 31 '13 at 07:18

2

for 4 being any number, we must set the range for it:

/^id\=[0-9]+/

\escape the equal-sign, plus after the number means 1 or even more.

answered Oct 31 '13 at 07:18

Levin

194
5

You don't have to escape `\\` really – Ilia Ross Oct 31 '13 at 07:26
1

@user2865738 Actually, it will not grab a number but result will be numerical string if you cast it to int it will be limited either to `(2^32) / 2 - 1` or `(2^64) / 2 - 1` number, depending you use 32 bit or 64 bit system, respectively. – Leri Oct 31 '13 at 07:28
1

@Ilia Rostovtsev you are right, i confused just now. and `\d` can instead `[0-9]`. – Levin Oct 31 '13 at 07:35

score 1 · Answer 2 · answered Oct 31 '13 at 09:38

You should go with the the following:

/id=(\d+)/g

Explanations:

id= - Literal id=
(\d+) - Capturing group 0-9 a character range between 0 and 9; + - repeating infinite times
/g - modifier: global. All matches (don't return on first match)

Example online

If you want to grab all ids and its values in PHP you could go with:

$string = "There are three ids: id=10 and id=12 and id=100";
preg_match_all("/id=(\d+)/", $string, $matches);
print_r($matches);

Output:

Array
(
    [0] => Array
        (
            [0] => id=10
            [1] => id=12
            [2] => id=100
        )

    [1] => Array
        (
            [0] => 10
            [1] => 12
            [2] => 100
        )

)

Example online

Note: If you want to match all you must use /g modifier. PHP doesn't support it but has other function for that which is preg_match_all. All you need to do is remove the g from the regex.

Catching ids and its values from a string with preg_match

2 Answers2

Explanations:

Output: