3v4l.org

run code in 300+ PHP versions simultaneously
<?php $z = 'bar'; $f = function ($y) use ($z) { echo $x ?? $y ?? $z; }; $f(null); $f('foo');
Output for 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
barfoo
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.40
Parse error: syntax error, unexpected '?' in /in/9lf4d on line 5
Process exited with code 255.

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