Why can't I reference a variable within a custom object?

Question

I'm just picking up Javascript, and I don't understand this problem.

I have created a custom object called DeleteReasonCodes with an instance variable called delReasonCodes, declared as an array. However, the inner methods can't seem to see this instance variable. Every time I try to run it, I get a delReasonCodes is not defined error.

Perhaps I'm just not understanding the Javascript scoping rules?

var DeleteReasonCodes = {

    delReasonCodes: [],

    get: function ()
    {
        return delReasonCodes;
    },

    add: function (code, desc)
    {
        delReasonCodes.push(new DeleteReasonCode(code, desc));
    }
};

score 2 · Accepted Answer · edited May 23 '17 at 11:55

2

No, javascript scoping belongs to functions (and nothing else).

The only variable you have created is DeleteReasonCodes, and you have assigned it an object with 3 properties. You can access them via a property accessor operator if you have a reference to the object. In your case, you could use this.delReasonCode or DeleteReasonCodes.delReasonCode - see this answer for the difference.

edited May 23 '17 at 11:55

Community

1
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answered Nov 05 '12 at 17:00

Bergi

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score 1 · Answer 2 · answered Nov 05 '12 at 17:01

You're treating a JavaScript object as you would a class in another language. Local-scope in JavaScript only resides inside functions, not objects. In your case, you need to access the data with a fully-qualified name:

DeleteReasonCodes.delReasonCodes.push();

score 0 · Answer 3 · edited Nov 05 '12 at 17:17

0

If you do this

delReasonCodes: [],

get: function() {
    return this.delReasonCodes;
},

edited Nov 05 '12 at 17:17

I Hate Lazy

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answered Nov 05 '12 at 17:02

Why can't I reference a variable within a custom object?

3 Answers3