JavaScript: Adding & Removing objects from array

Question

var layers = {};

//Add new layer
layer.markers = new L.Group();
layer.Name = t;

layers.layer = layer;

Gives an error layers.length is still 'undefined'. Why is it doing that ? I have verified in log that layers contains an item.

layers is not an array - it's a generic object, and objects have no length — georg
– georg, Commented Jan 23, 2014 at 12:32

MaxArt · Accepted Answer · 2014-01-23 12:35:18Z

1

layers is not an array. If you want to keep it as an object literal, and check if it's empty, try defining something like this:

Object.isEmpty = function(obj) {
    for (var p in obj)
        if (obj.hasOwnProperty(p)) return false;
    return true;
};

And use

if (!Object.isEmpty(layers)) { ...

instead.

answered Jan 23, 2014 at 12:35

MaxArt

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Comments

Peer · Accepted Answer · 2014-01-23 12:35:10Z

0

You're not adding to the array. The last line should be:

layers.push(layer);

answered Jan 23, 2014 at 12:35

Peer

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edisonthk · Accepted Answer · 2014-01-23 12:36:06Z

0

Simple question. layers is an object not an array.

What you needs to do is replace layers to following.

var layers = new Array();

And replace adding layer code from

layers.layer = layer;

to

layers.push(layer);

answered Jan 23, 2014 at 12:36

edisonthk

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