how to release closure's memory in javascript?

Question

A closure:

function test() {
  var count = 0;

  return function() {
    count++;
  };
}

As we all know, the count won\'t rele

Answer 1

All objects in javascript is garbage collected, regardless of weather they're involved in a closure or not. In your code above, if you do:

var x = test();

then of course the memory for count cannot be released because it may be used later by x. However if you do:

var x = test();
x = "";

the memory for count will be garbage collected sooner or later.

Also, if you do:

function foo () {
    var x = test();
    x();
}

foo();

the memory for count would also be garbage collected because x goes out of scope when foo() ends.

The best way to ensure you don't have memory leaks in javascript is to avoid global variables.

Note: The garbage collector in old versions of IE used a simple reference count which means that circular data structures are not garbage collected. This was fixed in either IE6 or IE7 and was never a problem in other javascript engines which normally use a mark-and-sweep garbage collector