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<?php $string = "{random_one}[SUBSTRING1] blah [SUBSTRINGX] blah blah {random_two}[SUBSTRING2] blah blah blah{random_one}[SUBSTRING3]"; preg_match_all("/{.+?}\[(.+?)\]/i", $string, $matches); var_dump($matches[1]);
Output for 7.0.0 - 7.0.23, 7.1.0 - 7.1.20, 7.2.6 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.19, 8.3.0 - 8.3.7
array(3) { [0]=> string(10) "SUBSTRING1" [1]=> string(10) "SUBSTRING2" [2]=> string(10) "SUBSTRING3" }
preferences:
121.22 ms | 404 KiB | 178 Q