3v4l.org

run code in 300+ PHP versions simultaneously
<?php $arr = array(1,2,3,4,5,6,7,8,9,10,'a','b','c','d','e','f','g','h','i','j'); $n=10; $tmp0 = $arr[0]; $tmp1 = $arr[$n]; for($i=0,$j=$n;$i<19;$i++,$j++){ $arr[$i]=$tmp0; $i++; $tmp0=$arr[$i]; $arr[$i]=$tmp1; $tmp1=$arr[$j+1]; } printIt($arr); function printIt($arr){ for($i=0;$i<count($arr);$i++){ echo($arr[$i]." "); } } ?>
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Warning: Undefined array key 20 in /in/UY8v5 on line 13 1 a 2 b 4 c 6 d 8 e 10 f b g d h f i h j
Output for 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33
Notice: Undefined offset: 20 in /in/UY8v5 on line 13 1 a 2 b 4 c 6 d 8 e 10 f b g d h f i h j
Output for 7.3.32 - 7.3.33
1 a 2 b 4 c 6 d 8 e 10 f b g d h f i h j
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
Notice: Undefined offset: 20 in /in/UY8v5 on line 13 1 a 2 b 4 c 6 d 8 e 10 f b g d h f i h j

preferences:
280.66 ms | 402 KiB | 460 Q