3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $i = 1; for($f = 0; $f <= 20; $f++) { echo "F".$f." = ".($i+$f)."\n"; $i++; }
based on r1MAE
Output for 4.3.0 - 7.1.0
F0 = 1 F1 = 3 F2 = 5 F3 = 7 F4 = 9 F5 = 11 F6 = 13 F7 = 15 F8 = 17 F9 = 19 F10 = 21 F11 = 23 F12 = 25 F13 = 27 F14 = 29 F15 = 31 F16 = 33 F17 = 35 F18 = 37 F19 = 39 F20 = 41