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Hari krishnan
Hari krishnan

Reputation: 2108

pass a variable to prototype Javascript

I want to send the selector value to the prototype. Currently i am using

var selector; //id of html element
function $(selector)
{
    if(window===this)
        return new $(selector);
    return this;
}
$.prototype={
    tooltip: function(){
        console.log(selector);
        //do calculations with the selector value
        return this;
    }
};

It is showing undefined.

Is there any way to pass variable?

Upvotes: 0

Views: 156

Answers (2)

Bergi
Bergi

Reputation: 664599

No, you cannot access it from the prototype methods. The selector parameter is a local variable to the constructor.

However, you can make it available as a property on your instance:

function $(selector) {
    if(!(this instanceof $))
        return new $(selector);

    this.selector = selector; // assigns the variable to a property
}
$.prototype.tooltip = function(){
    console.log(this.selector); // access the property on the instance
    //do calculations with the selector value
    return this;
};

Upvotes: 3

Ted Hopp
Ted Hopp

Reputation: 234807

I don't see where you are calling any of your functions or setting selector. However, one problem is that the formal function parameter selector in your definition of $ masks the outer variable also named selector. If you eliminate the function parameter, it should work better (assuming that you are also somewhere setting selector):

var selector; //id of html element
function $()
{
    if(window===this)
        return new $(selector);
    return this;
}
$.prototype={
    tooltip: function(){
        console.log(selector);
        //do calculations with the selector value
        return this;
    }
};

The way your code is written now, it is as if it were written as follows:

var selector; //id of html element
function $(x)
{
    if(window===this)
        return new $(x);
    return this;
}
$.prototype={
    tooltip: function(){
        console.log(selector);
        //do calculations with the selector value
        return this;
    }
};

Upvotes: 1

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