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<?php $a = array('a', 'b'); foreach ($a as $key => $val) { $a[2] .= 'a'; var_dump($a); } var_dump($a);
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 2 in /in/o0CZG on line 4 array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(1) "a" } array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(2) "aa" } array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(2) "aa" }
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: 2 in /in/o0CZG on line 4 array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(1) "a" } array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(2) "aa" } array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(2) "aa" }
Output for 7.3.32 - 7.3.33
array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(1) "a" } array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(2) "aa" } array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(2) "aa" }
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: 2 in /in/o0CZG on line 4 array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(1) "a" } array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(2) "aa" } array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(2) "aa" }

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