3v4l.org

run code in 300+ PHP versions simultaneously
<?php $f = fn($v) => $v; echo "foo {$f(0 ? 'true' : 'false')} bar\n\n"; echo "foo {(fn($v) => $v)(0 ? 'true' : 'false')} bar";
Output for 8.1.32, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
foo false bar Warning: Undefined variable $v in /in/gAN8v on line 5 Warning: Undefined variable $v in /in/gAN8v on line 5 foo {(fn() => )(0 ? 'true' : 'false')} bar

preferences:
55.6 ms | 406 KiB | 5 Q