D3.js Quick Start Guide

Defining GeoJSON

GeoJSON is just JSON data that has specific properties that are assigned specific data types. The following is an example of GeoJSON:

{
    "type": "Feature",
    "geometry": {
        "type": "Point",
        "coordinates": [125.6, 10.1]
    },
    "properties": {
        "name": "Dinagat Islands"
    }
}

In this example, we have one Feature, the geometry of which is a Point with the coordinates [125.6, 10.1]. Its name is Dinagat Islands. Each Feature will follow this general structure. An example, with the type as STRING, is as follows:

{
    "type": STRING,
    "geometry": {
        "type": STRING,
        "coordinates": ARRAY
    },
    "properties": OBJECT
}

We can also have a FeatureCollection, which includes many features grouped together in a features array. In the following code snippet, ...