CODEWITHSUNDEEP
javascriptnode.jsjavascript-objects
Suhail Gulzar
Suhail Gulzar

Reputation: 179

JS object property undefined when called within object the first time

Consider the following JS object, it has:

When the value of Pipe.x is printed immediately during Object creation, for some reason Pipe.x is undefined but when P.y() is called, after an object, the Object has been created, the Value of Pipe.x is 100, as it should have been in the first place.

var Pipe = {
    x: 100,

    p: function(){
        console.log('p says x is ' + this.x); // prints y says x is undefined
    }(),    // call immediately

    y: function(){
        console.log('y says x is ' + this.x);
    }
}

Pipe.y();    // prints y says x is 100

Is there any JS object property I'm missing which makes Pipe.p() print undefined and P.y() print 100?

Upvotes: 2

Views: 99

Answers (1)

sridhar..
sridhar..

Reputation: 2133

The this Context depends on how it is being called. When you call Pipe.y(), it is equivalent to obj.method() and this will be pointed to obj, in this case Pipe.

When p is being executed as IIFE, this is set to window and there is no x on window

Upvotes: 5

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