3v4l.org

run code in 300+ PHP versions simultaneously
<?php $number="123456"; for( $i=1,$l=strlen($number); $i<3; $i++ ) { $number[$l-$i] = '%'; var_dump($number); }
Output for 5.6.38, 7.1.0 - 7.1.22, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
string(6) "12345%" string(6) "1234%%"

preferences:
177.15 ms | 403 KiB | 167 Q