3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = [ 'H', 'E', 'L', 'L', 'O', ]; $string = implode("", $array); for ($i = 0; $i <= count($array); $i++) { echo substr($string, 0, $i)."\n"; }
Output for 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 - 8.1.31, 8.2.0 - 8.2.27, 8.3.0 - 8.3.15, 8.4.1 - 8.4.2
H HE HEL HELL HELLO

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137.03 ms | 407 KiB | 5 Q