3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = ["a" => "one", "b" => "two", "c" => "three"]; if (!function_exists("array_key_last")) { echo "Please upgrade to php 7.3"; } else { echo "First Key: " , key($array) , "\n"; echo "Last Key: " , array_key_last($array) , "\n"; next($array); echo "Second Key: " , key($array) , "\n"; echo "Last Key: " , array_key_last($array); }
Output for 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.16, 8.3.0 - 8.3.3
First Key: a Last Key: c Second Key: b Last Key: c
Output for 7.1.0 - 7.1.25, 7.2.0 - 7.2.33
Please upgrade to php 7.3

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