Javascript - How to null the Underlying Reference?

given this javascript code:

this.underlyingReference = {name: 'joe'};

this.nullMe(this.underlyingReference);

alert(this.underlyingReference.name);

function nullMe(variable) {
   variable = null;
}

Is there a way in Javascript for me to null this.underlyingReference using "variable"? I want to be able to null out variable and have the underlying reference be nulled and not simply null the reference to a reference.

I've read articles like this one http://snook.ca/archives/javascript/javascript_pass about Javascript's pass by reference functionality but it appears as though when you want to destroy the underlying reference the behavior is not what I have come to expect from references.

when execution passes the second line of code I want "this.underlyingReference" to be nulled out. Howeve开发者_运维知识库r the alert line shows that the underlying reference is still alive and kicking.

why not just assign null to that property:

this.underlyingReference = null;
alert(this.underlyingReference);// null

or, if you want to destroy the property, you can use delete:

delete this.underlyingReference;
alert(this.underlyingReference);// undefined

if you still want to have a function call, you can use this setup:

var NullMe = function(obj, propName) 
{
    obj[propName] = null;
    //OR, to destroy the prop:
    delete obj[propName];
}
NullMe(this, 'underlyingReference');

You can try

function nullMe(obj, reference){
    delete obj[reference];
}

nullMe(this, "underlyingReference");

Or

function nullMe(reference){
    delete this[reference];
}
nullMe.call(this, "underlyingReference");

There is a confusion between the "old by reference", used in Pascal and in C in some cases, and the "by reference" in java, javascript and most recent programming languages.

In javascript, a value is passed, and that value is a reference to the object. That mean you can change the object following that reference, but not change the reference itself.

If you need to do that in a method, then you need to do it "explicitly", for example :

this.nullMe("underlyingReference");
this.nullMe = function(name) {
    this[name] = null;
}

But it's a bit, well, over-engineering to have a method to set null :)