3v4l.org

run code in 300+ PHP versions simultaneously
<?php $arrayA = array(); $arrayB = array(&$arrayA); $arrayA[] = &$arrayB; var_dump($arrayA,$arrayB); var_dump(serialize($arrayA)); var_dump(json_encode($arrayA));
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
array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } string(34) "a:1:{i:0;a:1:{i:0;a:1:{i:0;R:2;}}}" bool(false)
Output for 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 - 7.3.33, 7.4.0 - 7.4.33
array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } string(34) "a:1:{i:0;a:1:{i:0;a:1:{i:0;R:2;}}}" bool(false)
Output for 5.2.14 - 5.2.17, 5.3.3 - 5.3.29, 5.4.0 - 5.4.45
array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } string(34) "a:1:{i:0;a:1:{i:0;a:1:{i:0;R:2;}}}" Warning: json_encode(): recursion detected in /in/2ahf1 on line 10 string(10) "[[[null]]]"
Output for 5.2.0 - 5.2.13, 5.3.0 - 5.3.2
array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } } } array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } } } string(34) "a:1:{i:0;a:1:{i:0;a:1:{i:0;R:2;}}}" Warning: json_encode(): recursion detected in /in/2ahf1 on line 10 string(10) "[[[null]]]"
Output for 5.0.0 - 5.0.5, 5.1.0 - 5.1.6
array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } } } array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } } } string(34) "a:1:{i:0;a:1:{i:0;a:1:{i:0;R:2;}}}" Fatal error: Call to undefined function json_encode() in /in/2ahf1 on line 10
Process exited with code 255.
Output for 4.4.5 - 4.4.9
array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } } } array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } } } string(34) "a:1:{i:0;a:1:{i:0;a:1:{i:0;R:2;}}}" Fatal error: Call to undefined function: json_encode() in /in/2ahf1 on line 10
Process exited with code 255.
Output for 4.3.2 - 4.3.11, 4.4.0 - 4.4.4
array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } } } array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } } } string(34) "a:1:{i:0;a:1:{i:0;a:1:{i:0;R:2;}}}" Fatal error: Call to undefined function: json_encode() in /in/2ahf1 on line 10
Process exited with code 255.
Output for 4.3.0 - 4.3.1
array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } } } array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> &array(1) { [0]=> *RECURSION* } } } } } string(34) "a:1:{i:0;a:1:{i:0;a:1:{i:0;R:2;}}}" Fatal error: Call to undefined function: json_encode() in /in/2ahf1 on line 10

preferences:
340.99 ms | 402 KiB | 458 Q