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<?php $string = '--'; $doesNotMatchInPhp7 = '/(?|(---)|(-))\1/'; $matchesInPhp7 = '/(?|(-)|(---))\1/'; var_dump(preg_match($doesNotMatchInPhp7, $string)); var_dump(preg_match($matchesInPhp7, $string));
Output for 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.31, 8.2.0 - 8.2.27, 8.3.0 - 8.3.15, 8.4.1 - 8.4.2
int(1) int(1)
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33
int(0) int(1)
preferences:
80.89 ms | 407 KiB | 5 Q