note 81702 added to function.unset

Since unset() is a language construct, it cannot be passed anything other than a variable. It's sole purpose is to "unset" this variable, ie. to remove it from the current scope and destroy it's associated data. This is true especially for reference variables, where not the actual value is destroyed but the reference to that value. This is why you can't wrap 'unset()' in a user defined function: You would either unset a copy of the data if the parameter is passed by value, or you would just unset the reference variable within the functions scope if the parameter is passed by reference. There is no workaround for that, as you cannot pass 'scope' to a function in PHP. Such a function can only work for variables that exist in a common or global scope (compare 'unset($_GLOBALS[variable])'). I don't know how PHP handles garbage collection internally, but I guess this behavior can result in a huge memory leak: if a value variable goes out of scope with a second variable still holding a reference to the in-memory value, then unsetting that reference would still hold the value in memory but potentially unset the last reference to that in-memory data, hence: occupied memory that is rendered useless as you cannot reference it anymore. ---- Server IP: 69.147.83.197 Probable Submitter: 84.179.180.62 ---- Manual Page -- http://www.php.net/manual/en/function.unset.php Edit -- https://master.php.net/note/edit/81702 Del: integrated -- https://master.php.net/note/delete/81702/integrated Del: useless -- https://master.php.net/note/delete/81702/useless Del: bad code -- https://master.php.net/note/delete/81702/bad+code Del: spam -- https://master.php.net/note/delete/81702/spam Del: non-english -- https://master.php.net/note/delete/81702/non-english Del: in docs -- https://master.php.net/note/delete/81702/in+docs Del: other reasons-- https://master.php.net/note/delete/81702 Reject -- https://master.php.net/note/reject/81702 Search -- https://master.php.net/manage/user-notes.php