variable defined in prototype are shared accross objects?

Question

I have create object lik

e this
testObj.prototype = {
    cVar: 15,
    init: function(c){
        /*initialization code*/
        this.cVar = c;
    }
};

var a = new testObj(10);
var b = new testObj(20);

Now both object's cVar values is 20. Are they sharing the variable? How i can get seperate variable for each object?

Ionuț G. Stan · Accepted Answer · 2010-10-26 09:04:28Z

6

Yes, they're shared. For separate properties, define them inside the constructor:

function Ctor() {
    this.notShared = 1;
};

Ctor.prototype.shared = 2;

answered Oct 26, 2010 at 9:04

Ionuț G. Stan

180k19 gold badges196 silver badges206 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

coure2011 Over a year ago

how to access this.notShared? inside prototype.init?

Ionuț G. Stan Over a year ago

this.notShared, but you must call the constructor before calling init.

Bharat Khatri Over a year ago

This example is slightly confusing.

var o1 = new Ctor(); var o2 = new Ctor(); o1.shared += 1; console.log("o1.shared = " + o1.shared + ", o2.shared = " + o2.shared);

gives o1.shared = 3, o2.shared = 2. I know this is obvious, but the shared sense of it doesn't come out through this example. It'd be better if the example demonstrated the shared state by using Ctor.prototype.shared = {}

Derek Morrison Over a year ago

@BharatKhatri makes a good point. If you modify the shared variable on one of the instantiated objects, then it becomes "unshared" on that object (as the variable has been re-assigned on it).

Collectives™ on Stack Overflow

variable defined in prototype are shared accross objects?

1 Answer 1

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related