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run code in 300+ PHP versions simultaneously
<?php function foo(&$str) { $str = 'xyz'; return $str; } $o = "abc"; foo($o); var_dump($o); $o = "abc"; call_user_func('foo', $o); var_dump($o); $o = "abc"; call_user_func('foo', [$o]); var_dump($o); $a[] = "abc"; $a[] = "abc"; $a[] = "abc"; call_user_func('foo', array_slice($a, 0, 1)); var_dump($a);
Output for 8.0.0 - 8.0.3
string(3) "xyz" Warning: foo(): Argument #1 ($str) must be passed by reference, value given in /in/OEOA1 on line 12 string(3) "abc" Warning: foo(): Argument #1 ($str) must be passed by reference, value given in /in/OEOA1 on line 15 string(3) "abc" Warning: foo(): Argument #1 ($str) must be passed by reference, value given in /in/OEOA1 on line 21 array(3) { [0]=> string(3) "abc" [1]=> string(3) "abc" [2]=> string(3) "abc" }
Output for 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.16 - 7.3.28, 7.4.0 - 7.4.16
string(3) "xyz" Warning: Parameter 1 to foo() expected to be a reference, value given in /in/OEOA1 on line 12 string(3) "abc" Warning: Parameter 1 to foo() expected to be a reference, value given in /in/OEOA1 on line 15 string(3) "abc" Warning: Parameter 1 to foo() expected to be a reference, value given in /in/OEOA1 on line 21 array(3) { [0]=> string(3) "abc" [1]=> string(3) "abc" [2]=> string(3) "abc" }
Output for 7.0.0 - 7.0.8, 7.0.10 - 7.0.20
string(3) "xyz" string(3) "xyz" string(3) "abc" Warning: Parameter 1 to foo() expected to be a reference, value given in /in/OEOA1 on line 21 array(3) { [0]=> string(3) "abc" [1]=> string(3) "abc" [2]=> string(3) "abc" }
Output for 7.0.9
string(3) "xyz" Warning: Parameter 1 to foo() expected to be a reference, value given in /in/OEOA1 on line 12 string(3) "abc" string(3) "abc" Warning: Parameter 1 to foo() expected to be a reference, value given in /in/OEOA1 on line 21 array(3) { [0]=> string(3) "abc" [1]=> string(3) "abc" [2]=> string(3) "abc" }
Output for 5.6.0 - 5.6.26
string(3) "xyz" Warning: Parameter 1 to foo() expected to be a reference, value given in /in/OEOA1 on line 12 string(3) "abc" string(3) "abc" array(3) { [0]=> string(3) "abc" [1]=> string(3) "abc" [2]=> string(3) "abc" }