3v4l.org

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<?php $number = 1; $answer = "p__vä"; $letter = mb_substr( $answer , 2, 1 ); $answer = preg_replace('/'.$letter.'/u', '_',$answer,1); echo $answer;
Output for 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 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
p__vä

preferences:
246.62 ms | 404 KiB | 326 Q