3v4l.org

run code in 300+ PHP versions simultaneously
<?php function s($rad){ return M_PI*(pow($rad/2,2)); } $r1=4; $r2=10; $r3=22; echo s($r1); echo "<br>"; $a=$r2; echo s($a); echo "<br>"; echo s(22); ?>

preferences:
28.37 ms | 402 KiB | 5 Q