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<?php $a = array(a => 'a', b => 'b' ); $b = array(a => 'a_p', b => 'b_p' ); $c = array_merge($a, $b); var_dump($c);
Output for 7.2.0
Warning: Use of undefined constant a - assumed 'a' (this will throw an Error in a future version of PHP) in /in/I06J2 on line 3 Warning: Use of undefined constant b - assumed 'b' (this will throw an Error in a future version of PHP) in /in/I06J2 on line 3 Warning: Use of undefined constant a - assumed 'a' (this will throw an Error in a future version of PHP) in /in/I06J2 on line 4 Warning: Use of undefined constant b - assumed 'b' (this will throw an Error in a future version of PHP) in /in/I06J2 on line 4 array(2) { ["a"]=> string(3) "a_p" ["b"]=> string(3) "b_p" }
Output for 4.3.0 - 7.1.7
Notice: Use of undefined constant a - assumed 'a' in /in/I06J2 on line 3 Notice: Use of undefined constant b - assumed 'b' in /in/I06J2 on line 3 Notice: Use of undefined constant a - assumed 'a' in /in/I06J2 on line 4 Notice: Use of undefined constant b - assumed 'b' in /in/I06J2 on line 4 array(2) { ["a"]=> string(3) "a_p" ["b"]=> string(3) "b_p" }