3v4l.org

run code in 300+ PHP versions simultaneously
<?php function f(&$x) {echo $x;} function g() {return 2;} $x = 1; f(1); echo $x;
Output for 8.3.0 - 8.3.6
Fatal error: Uncaught Error: f(): Argument #1 ($x) could not be passed by reference in /in/OKcJR:5 Stack trace: #0 {main} thrown in /in/OKcJR on line 5
Process exited with code 255.
Output for 8.1.23 - 8.1.28, 8.2.10 - 8.2.18
Fatal error: Uncaught Error: f(): Argument #1 ($x) cannot be passed by reference in /in/OKcJR:5 Stack trace: #0 {main} thrown in /in/OKcJR on line 5
Process exited with code 255.
Output for 5.3.0 - 5.3.27, 5.4.0 - 5.4.21
Fatal error: Only variables can be passed by reference in /in/OKcJR on line 5
Process exited with code 255.

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