3v4l.org

run code in 300+ PHP versions simultaneously
<?php for( $i = 1; $i < 20; $i++ ) { echo 0.5 * ( 1 * $i + pow( -1, $i ) - 1 ) . ', '; }
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 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 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
-0.5, 1, 0.5, 2, 1.5, 3, 2.5, 4, 3.5, 5, 4.5, 6, 5.5, 7, 6.5, 8, 7.5, 9, 8.5,
preferences:
270.56 ms | 406 KiB | 354 Q