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<?php $a = array("one" => 1, "two" => 2); $firstKey = reset(array_keys($a)); echo $firstKey . "\n";
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.12 - 7.3.31, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
Notice: Only variables should be passed by reference in /in/0G2UT on line 3 one
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.4, 7.3.32 - 7.3.33
one
Output for 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.37, 5.6.0 - 5.6.28
Strict Standards: Only variables should be passed by reference in /in/0G2UT on line 3 one
Output for 5.0.5
Fatal error: Only variables can be passed by reference in /in/0G2UT on line 3
Process exited with code 255.

preferences:
255.32 ms | 401 KiB | 348 Q