access nested value in json

Question

I want to access the coordinates:

{
    "name":"String",
    "type":"FeatureCollection",
    "features":[
        {"type":"Feature", "geometry": {"type":"Point", "coordinates":[10,11]}},
        {...},
        {...}]
}

I already tried:

var jsonfile = $.getJSON("myjsonfile.json");
for(var i = 0, l = jsonfile.features; i < l; i++) {
  var obj = json.features[i];
  console.log(obj.coordinates[1]);
}

But this doesn't work. I don't know why...

`obj.features[0].geometry.coordinates` by the looks of it. – Andy Jun 24 '15 at 13:43 — Andy, Jun 24 '15 at 13:43

Andy · Accepted Answer · 2015-06-24T14:04:50.800

1

obj.features[0].geometry.coordinates;

The object contains an array called features the first element of which is another object called geometry, one property of which is an array called coordinates.

So, the iteration would be something like:

var jsonfile = $.getJSON("myjsonfile.json", function (data) {
    for (var i = 0, l = data.features.length; i < l; i++) {
        var coords = data.features[i].geometry.coordinates;
        var lat = coords[0];
        var lng = coords[1];
        // plot lat, lng
    }
});

edited Jun 24 '15 at 14:04

answered Jun 24 '15 at 13:45

Andy

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I think, OP want all the `coordinates` from the object array – Tushar Jun 24 '15 at 13:48
`getJSON` is asynchronous. Even if he'd fix the loop, this still wouldn't work. – Cerbrus Jun 24 '15 at 13:50
i get undefined in Chrome – plasmid0h Jun 24 '15 at 13:51
Yeah, I missed that the first time round. @plasmid0h, the answer shows you how to use `getJSON` properly for an asynchronous request. – Andy Jun 24 '15 at 13:53
i still get undefined in the console ? :/ – plasmid0h Jun 24 '15 at 14:00
@plasmid0h, doh, I missed the length attribute off the loop. See if it works now. [Here's a demo that mimics `getJSON`](http://jsfiddle.net/o7o5u2w7/2/). You should check that you're actually receiving data from `getJSON`. – Andy Jun 24 '15 at 14:06
sorry, i don't understand. – plasmid0h Jun 24 '15 at 14:09
In your callback, check that you're actually getting data returned before you loop over it. [See the example here](http://jsfiddle.net/o7o5u2w7/3/). If you're not, that's a separate problem. – Andy Jun 24 '15 at 14:17
Ahhh.... Thanks ! now i understood :) – plasmid0h Jun 29 '15 at 00:53

access nested value in json

1 Answers1