topic Re: Removing duplicates from an array in ArcGIS JavaScript Maps SDK Questions

Removing duplicates from an array

joepublic — Tue, 04 Nov 2014 04:37:28 GMT

Robert, et al

On further testing (click on the 3rd button "city models") I see that there are duplicates in my object ids which are being used to create the countries layer. This causing my application to run slow. A look at the console.log of the featureCollection on line 300 rquery.run(function(error, featureCollection, response) will show what I mean

Is there a way to remove the duplicates (so there is only one objectid per country) before the layer is added to my map?

Spec attached

Re: Removing duplicates from an array

KenBuja — Mon, 10 Nov 2014 15:19:18 GMT

There are a couple of ways to do this, like this or this

Re: Removing duplicates from an array

joepublic — Mon, 10 Nov 2014 16:18:37 GMT

Thanks for the suggestions Ken.

But my question is for a specific case.

The problem is here: rquery.objectIds();... This creates an

array of opjectIds with dupes.

I am trying to remove the dupes before I pass the array to :

countries = L.geoJson(featureCollection).addTo(map);

Re: Removing duplicates from an array

ReneRubalcava — Mon, 10 Nov 2014 16:40:50 GMT

The above examples could be tweaked a little for that.

var unique = {};
var distinctFeatures = featuresCollection.features.filter(function(feature) {
  var oid = feature.properties.OBJECTID;
  if (!unique[oid]) {
    unique[oid] = oid;
    return true;
  }
  return false;
});
featureCollection.features = distinctFeatures;

That's a quick and dirty way of doing it based on the example Ken provided.

Re: Removing duplicates from an array

joepublic — Mon, 10 Nov 2014 17:02:25 GMT

Thanks Rene!!

I work with this and let you know if I still problems

Chris