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<?php // can be anything, even always false regex $regex = '~(?<=t)(?<=f)x()(?<named>y)~u'; // add one capturing group to the end so all capture group keys // are present in the $matches $regex = preg_replace('~^(.)(.*)\K(\1\w*$)~', '|()$3', $regex); var_dump($regex); preg_match($regex, '', $matches); print_r($matches);
Output for 4.4.9, 5.2.4 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.27, 8.4.1 - 8.4.14
string(32) "~(?<=t)(?<=f)x()(?<named>y)|()~u" Array ( [0] => [1] => [named] => [2] => [3] => )
Output for 4.4.6 - 4.4.8, 5.2.2 - 5.2.3
string(29) "~(?<=t)(?<=f)x()(?<named>y)~u" Array ( )
Output for 5.2.0 - 5.2.1
string(29) "~(?<=t)(?<=f)x()(?<named>y)~u" Warning: preg_match(): Compilation failed: unrecognized character after (?< at offset 18 in /in/sOXbn on line 11
Output for 4.3.11, 4.4.0 - 4.4.5, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6
string(29) "~(?<=t)(?<=f)x()(?<named>y)~u" Warning: preg_match(): Compilation failed: unrecognized character after (?< at offset 18 in /in/sOXbn on line 11 Array ( )
Output for 4.3.0 - 4.3.10
string(29) "~(?<=t)(?<=f)x()(?<named>y)~u" Warning: Compilation failed: unrecognized character after (?< at offset 18 in /in/sOXbn on line 11 Array ( )
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125.19 ms | 411 KiB | 5 Q