How do you remove objects?

[mrjohn]

Hey!

I'm working on a javascript project which will run on a single html page, and I'm using lots of objects. The program will create new instances of these objects during runtime. However, for efficiency, I need a way to get rid of the old ones. Is there any way to do this?

[dlite922]

by objects you mean elements?

any html element can be cleared with the innerHTML() method. Just set it to an empty string.

[mrjohn]

Ach, I'm sorry, I meant this sort of object

function spaceShip(hull, shields, weapons)
            {
                this.hull = hull;
                this.shields = shields;
                this.weapons = weapons;
                this.crew = 5;
            }
var nightHawk = new spaceShip("Titanium", 16, phasers);
 

I'm not sure what it is called, but I was wondering how to remove instances of such an object.

[mrhoo]

If you declare your objects as globals with the var keyword, as in your example, you cannot delete them. The nearest you can get is to set them to undefined.

[mrjohn]

Oh dear. That is a bit of a bummer. What if instead I put them in an array, like this?

var fleet = new Array(3);
            fleet[0] = new spaceShip("Iron", 9, phasers);
            fleet[1] = new spaceShip("Titanium", 13, phasers);
            fleet[2] = new spaceShip("Aluminum", 2, phasers);
            fleet.splice(1,1);
 

When splice is run, would the object be removed then? Or would it just be floating around somewhere?

[dmjpro]

Object removing means .. you want to say your JS Engine to free up the memory(occupied by an instance) when the object no longer needed.
Did you mean that?

[mrjohn]

Yeah, thats what I meant.

[acoder]

Where possible, use the delete operator.

[mrjohn]

Awesome! Thank you very much.