3v4l.org

run code in 300+ PHP versions simultaneously
<?php $v1 = 5; $v2 = '5-4'; $time = microtime(1); $i = 0; @ob_start(); while($i++ < 1000000) echo 'a','b','c','d','e'; @ob_endclean(); echo (microtime(1)-$time)." seconds for commas"; echo "\n"; $time = microtime(1); $i = 0; @ob_start(); while($i++ < 1000000) echo 'a'.'b'.'c'.'d'.'e'; @ob_endclean(); echo (microtime(1)-$time)." seconds for dot"; function donull($v){};

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31.49 ms | 402 KiB | 5 Q