How to access a specific object in javascript?

Question

I am a bit of a noob when it comes to this. I am using JSON to define a class/object called product and I am not sure how to pass arguments to access a certain part of that object. Pardon me for not being able to explain it better. Hopefully my code sample will help:

var product = {
    p14lb: {
        one: 10.00,
        two: 20.00,
        three: 30.00,
        four: 40.00,
        five: 50.00,
        six: 60.00,
        colorCharge: 2.00
    },
    p20lb: {
        one: 20.00,
        two: 30.00,
        three: 40.00,
        four: 50.00,
        five: 60.00,
        six: 70.00,
        colorCharge: 1.00
    },
    getPrice: function (productQty,colorQty) {

        // I can get the values like this        
        return this.p20lb.one * productQty;

        // but i'd like to be able to pass in the value of what object I want to access
        // so instead of hard coding p20lb.one, 'p20lb' would be an argument I could pass
        // to getPrice, and 'one' would also be an argument

    }
};

This is how I am accessing it currently, works great.

var myProduct = product.getPrice(144,2);

As I said in the comment in the above code sample, I'd like to not hard code p20lb.one, 'p20lb' would be an argument I could pass to getPrice, and 'one' would also be an argument. So maybe something like this:

getPrice: function (productQty,colorQty,productName,tier) {

    return this.productName.tier * productQty;

}

var myProduct = product.getPrice(144,2,'14lb','two');

But that is no go, I get undefined no matter what I do. I'm clearly a noob when it comes to this. Is what I'm trying to do possible? If so, can you point me in the right direction? Thanks!

BTW: What you refer to is called "object literal", not JSON. JSON is a very strict string format that can be understood by JavaScript's eval(). Your sample is valid JavaScript, but definitely not JSON-compliant. — Tomalak
– Tomalak, Commented Jan 21, 2011 at 0:49
+1 Cool, thanks for that! I was using this as reference (see #2) phpied.com/3-ways-to-define-a-javascript-class — jyoseph
– jyoseph, Commented Jan 21, 2011 at 1:06
Ah, and now that I read the comments on the article I linked, someone also pointed that out to the author, too. Good to know! — jyoseph
– jyoseph, Commented Jan 21, 2011 at 1:09

user236139 · Accepted Answer · 2011-01-21 00:45:21Z

4

Try this[productName][tier] instead. In JavaScript, the dot notation and bracket notation are identical. That is, obj.a is the same as obj['a'].

answered Jan 21, 2011 at 0:45

user236139

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Tomalak · Accepted Answer · 2011-01-21 00:45:36Z

1

Simple.

getPrice: function (productQty,colorQty,productName,tier) {

    return this[productName][tier] * productQty;

}

Objects can be accessed in array notation. Don't forget to wrap it in a try-catch block to handle the cases where a certain key combination does not exist.

answered Jan 21, 2011 at 0:45

Tomalak

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Comments

Rachel McMahan · Accepted Answer · 2011-01-21 00:51:39Z

0

Can you just do:

var colorQty = product.p20lb.one;
var myProduct = product.getPrice(144, colorQty);

getPrice: function (productQty, colorQty) {
    return productQty * colorQty;
}

answered Jan 21, 2011 at 0:51

Rachel McMahan

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