3v4l.org

run code in 300+ PHP versions simultaneously
<?php function is_intstr($val, $negative=false) { return preg_match("/^".($negative?"-?":"")."(0|[1-9][0-9]*)$/", $val); } foreach(range(-10, 20) as $n) { echo $n*$n*$n; echo " - "; echo is_intstr($n*$n*$n, false); echo "\n"; }
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 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 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
-1000 - 0 -729 - 0 -512 - 0 -343 - 0 -216 - 0 -125 - 0 -64 - 0 -27 - 0 -8 - 0 -1 - 0 0 - 1 1 - 1 8 - 1 27 - 1 64 - 1 125 - 1 216 - 1 343 - 1 512 - 1 729 - 1 1000 - 1 1331 - 1 1728 - 1 2197 - 1 2744 - 1 3375 - 1 4096 - 1 4913 - 1 5832 - 1 6859 - 1 8000 - 1
preferences:
207.2 ms | 406 KiB | 311 Q