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kana/fukusayou.php

Created August 17, 2017 12:38
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fukusayou.php
<?php
$a = 1;
debug_zval_dump($a);
//==> long(1) refcount(2)
// Novice: Huh? Why is refcount 2? The value is only pointed by $a, so refcount must be 1!
// Tatsujin: PHP uses copy-on-write. The value is passed by value to debug_zval_dump.
// It doesn't modify the passed value. The value is shared by $a and debug_zval_dump.
// Therefore refcount is 2.
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