Extracting A Substring That Is Wrapped By Some Characters

What is best practice to select content between a pair of delimiter using regular expression excluding the delimiters in PHP and JS? aassssd [dddd] fff ffff (delimiter=[..]) outp

Solution 1:

I would use the non-greedy .*? which captures everything upto the end delimiter :

$str = 'aassssd QddddQ fff ffff';
preg_match_all('/[Q](.*?)[Q]/', $str, $out, PREG_PATTERN_ORDER);
var_dump($out); 

produces :

Array
(
    [0] => Array
        (
            [0] => QddddQ
        )

    [1] => Array
        (
            [0] => dddd
        )

)

You would need to escape the [ and ] delimiters : /[\[](.*?)[\]]/

This uses a single capture group (.*?) so the output you need is in position 1 in the output array.

Solution 2:

aassssd [dddd] fff ffff (delimiter=[..])   output -> dddd

RegEx for PHP:

(?<=\[).*?(?=\])

RegEx for JS (works in PHP too):

[^\[]*?(?=\])