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run code in 300+ PHP versions simultaneously
<?php function z($a) { $a[0]=1; //now we changed array, so PHP should make it's copy: debug_zval_dump($a); return $a; } $a = [ 'a', 'b', 'c' ]; debug_zval_dump($a); foreach(z($a) as &$x) { $x .= 'q'; } print_r($a);
Output for 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
array(3) refcount(3){ [0]=> string(1) "a" interned [1]=> string(1) "b" interned [2]=> string(1) "c" interned } array(3) refcount(2){ [0]=> int(1) [1]=> string(1) "b" interned [2]=> string(1) "c" interned } Array ( [0] => a [1] => b [2] => c )
Output for 7.3.12 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30
array(3) refcount(3){ [0]=> string(1) "a" refcount(1) [1]=> string(1) "b" refcount(1) [2]=> string(1) "c" refcount(1) } array(3) refcount(2){ [0]=> int(1) [1]=> string(1) "b" refcount(1) [2]=> string(1) "c" refcount(1) } Array ( [0] => a [1] => b [2] => c )
Output for 7.1.0 - 7.1.20, 7.2.0 - 7.2.33
array(3) refcount(3){ [0]=> string(1) "a" refcount(1) [1]=> string(1) "b" refcount(1) [2]=> string(1) "c" refcount(1) } array(3) refcount(2){ [0]=> int(1) [1]=> string(1) "b" refcount(2) [2]=> string(1) "c" refcount(2) } Array ( [0] => a [1] => b [2] => c )
Output for 7.0.0 - 7.0.20
array(3) refcount(2){ [0]=> string(1) "a" refcount(2) [1]=> string(1) "b" refcount(2) [2]=> string(1) "c" refcount(2) } array(3) refcount(2){ [0]=> int(1) [1]=> string(1) "b" refcount(3) [2]=> string(1) "c" refcount(3) } Array ( [0] => a [1] => b [2] => c )
Output for 5.5.24 - 5.5.35, 5.6.7 - 5.6.28
array(3) refcount(2){ [0]=> string(1) "a" refcount(1) [1]=> string(1) "b" refcount(1) [2]=> string(1) "c" refcount(1) } array(3) refcount(2){ [0]=> long(1) refcount(1) [1]=> string(1) "b" refcount(2) [2]=> string(1) "c" refcount(2) } Array ( [0] => a [1] => b [2] => c )
Output for 5.4.0 - 5.4.45
Fatal error: Cannot create references to elements of a temporary array expression in /in/dldTB on line 14
Process exited with code 255.
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/dldTB on line 12
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/dldTB on line 12
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/dldTB on line 12
Process exited with code 255.

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