javascript access multidimensional object not working

Question

I have an object:

var Obj = [{
    id: "",
    position: {
        cartesian: [],
        polar: [],
        bob: "INERTIAL"
    }
}];

When I go to set obt.id

Obj.id="sam/reconnaissance - "+samName;

It works fine.

However when I go to access Obj.position.cartesian

(Obj.position.cartesian).push(fooBar[i][t][p]);

I get this error:

     (Obj.position.cartesian).push(fooBar[i][t][p]);
                            ^
TypeError: Cannot read property 'cartesian' of undefined

Why? I have tried Obj['position']['cartesian'] and still nothing

What am I doing wrong?

tanaydin · Accepted Answer · 2016-09-05 17:46:00Z

1

Obj is not an object, it is an Array so you have to access first element with index 0. Try it like

Obj[0]['position']['cartesian']

answered Sep 5, 2016 at 17:46

tanaydin

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1 Comment

I will for sure! I got to wait 10 more mins stackoverflow says ;)

Huntro · Accepted Answer · 2016-09-05 17:51:33Z

1

You aren't using an object, you are using an array.

An object looks like this:

var obj = {
    id: 0
};

What you have is an object within an array: (note [)

var obj = [{id: 0}];

answered Sep 5, 2016 at 17:51

Huntro

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Manoj · Accepted Answer · 2016-09-05 18:20:16Z

1

Obj is an array with single element as object, hence to access position you can use any of these syntax

    Obj[0]['position']['cartesian']
    Obj[0].position.cartesian

Again cartesian is an array hence to call push you can use

    Obj[0]['position']['cartesian'].push(foobar[i][t][p])
    Obj[0].position.cartesian.push(foobar[i][t][p])

answered Sep 5, 2016 at 18:20

Manoj

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