Geojson Feature

GeoJSON features’ geometry can be represented as a discriminated union based on their geometry type:


type GeoJSONFeature = 
  | PointFeature
  | LineStringFeature
  | PolygonFeature
  | MultiPolygonFeature;

type PointFeature = {
  type: "Feature";
  geometry: {
    type: "Point";
    coordinates: [number, number] | [number, number, number]; // [longitude, latitude] or [longitude, latitude, altitude]
  };
  properties: Record<string, any>;
};

type LineStringFeature = {
  type: "Feature";
  geometry: {
    type: "LineString";
    coordinates: Array<[number, number] | [number, number, number]>;
  };
  properties: Record<string, any>;
};

type PolygonFeature = {
  type: "Feature";
  geometry: {
    type: "Polygon";
    coordinates: Array<Array<[number, number] | [number, number, number]>>;
  };
  properties: Record<string, any>;
};

type MultiPolygonFeature = {
  type: "Feature";
  geometry: {
    type: "MultiPolygon";
    coordinates: Array<Array<Array<[number, number] | [number, number, number]>>>;
  };
  properties: Record<string, any>;
};

Note: All coordinate arrays support both 2D (longitude, latitude) and 3D (longitude, latitude, altitude) formats. The third coordinate (z) represents elevation or altitude.

Geojson Point


{
  "type": "Feature",
  "geometry": {
    "type": "Point",
    "coordinates": [longitude, latitude]
  },
  "properties": {}
}

Geojson Line


{
  "type": "Feature",
  "geometry": {
    "type": "LineString",
    "coordinates": [
      [longitude1, latitude1],
      [longitude2, latitude2]
    ]
  },
  "properties": {}
}

Geojson Polygon


{
  "type": "Feature",
  "geometry": {
    "type": "Polygon",
    "coordinates": [
      [
        [longitude1, latitude1],
        [longitude2, latitude2],
        [longitude3, latitude3],
        [longitude1, latitude1]
      ]
    ]
  },
  "properties": {}
}

Geojson MultiPolygon


{
  "type": "Feature",
  "geometry": {
    "type": "MultiPolygon",
    "coordinates": [
      [
        [
          [longitude1, latitude1],
          [longitude2, latitude2],
          [longitude3, latitude3],
          [longitude1, latitude1]
        ]
      ],
      [
        [
          [longitude4, latitude4],
          [longitude5, latitude5],
          [longitude6, latitude6],
          [longitude4, latitude4]
        ]
      ]
    ]
  },
  "properties": {}
}