3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 'x'; debug_zval_dump($a); b($a); function b($a){ debug_zval_dump($a);//refcount=4 why not 3? }
Output for 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
string(1) "x" interned string(1) "x" interned
Output for 7.0.0 - 7.0.20, 7.1.0, 7.1.7 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30
string(1) "x" refcount(1) string(1) "x" refcount(1)
Output for 7.1.5 - 7.1.6
string(1) "x" refcount(3) string(1) "x" refcount(4)
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.35, 5.6.0 - 5.6.28
string(1) "x" refcount(2) string(1) "x" refcount(4)
preferences:
221.73 ms | 403 KiB | 360 Q