3v4l.org

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<?php $a = [ 0 => 'a', 1 => 'b', 2=> 'c']; $b = [ 1 => 'b', 2 => 'c', 3=> 'd']; var_dump(array_unique(array_merge($a, $b)));
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 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
array(4) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(1) "c" [5]=> string(1) "d" }
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29
Parse error: syntax error, unexpected '[' in /in/L4MYY on line 3
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1, 5.0.0 - 5.0.5
Parse error: parse error, unexpected '[' in /in/L4MYY on line 3
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/L4MYY on line 3
Process exited with code 255.

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