3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array(); $b = array(); $c = array(); for ($x=1,$n=0;$x<20;$x=$x+3) { $a[] = $x; $b[] = $x+1; $c[] = $x+2; //$x = $x+3; } print_r($a); echo "\n\n"; print_r($b); echo "\n\n"; print_r($c); echo "\n\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, 5.5.0 - 5.5.38, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.12 - 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
Array ( [0] => 1 [1] => 4 [2] => 7 [3] => 10 [4] => 13 [5] => 16 [6] => 19 ) Array ( [0] => 2 [1] => 5 [2] => 8 [3] => 11 [4] => 14 [5] => 17 [6] => 20 ) Array ( [0] => 3 [1] => 6 [2] => 9 [3] => 12 [4] => 15 [5] => 18 [6] => 21 )
preferences:
232.6 ms | 406 KiB | 356 Q