$a="hello"; $b= &$a; unset($b); $b="world"; echo $a;的结果是什么?( )
$a="hello";xdebug_debug_zval('a'):(refcount=1, is_ref=0),string 'hello' (length=5)$b= &$a;xdebug_debug_zval('a'):(refcount=2, is_ref=1),string 'hello' (length=5)unset($b);xdebug_debug_zval('a'):(refcount=1, is_ref=0),string 'hello' (length=5)