What happens when node setTimeout callback becomes null

Question

What happens when node setTimeout callback becomes null

I have a question about callbacks. I have an object which one function is used as a setTimeout callback and that object can be deleted before the callback fires. Will node know not to call it when timeout occurs or will it keep a reference and call it anyway?

node.js
callback

Answer 1

Did some tests and it looks like node keeps a reference to the object and fires the callback.

Answer 2

After "delete" the object is not necessarily deleted, you are only deleting your reference of it. The method will still be callable.

> cat test.js
var a = {                                                                                                                                                                                          
    method: function() {
        console.log('a' + a.property)   
    },
    property: '1'
}
setTimeout(a.method, 1000);
delete a;

> node test.js                                                                                                                                                                        
a1