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<?php $str = "еще"; $valid_string_expr = '/^[а-я]+$/u'; var_dump(preg_match($valid_string_expr, $str)); $str = "ещё"; var_dump(preg_match($valid_string_expr, $str));
Output for 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 - 8.3.25, 8.4.1 - 8.4.12
int(1) int(0)
preferences:
138.26 ms | 408 KiB | 5 Q