KBE3D / KBCore / turf / featureReduce

函数: featureReduce()

featureReduce<Reducer, G, P>(geojson: Feature<G, P> | FeatureCollection<G, P> | Feature<GeometryCollection<Geometry>, P>, callback: (previousValue: Reducer, currentFeature: Feature<G, P>, featureIndex: number) => Reducer, initialValue?: Reducer): Reducer

Function

Reduce features in any GeoJSON object, similar to Array.reduce().

类型参数

Reducer

Reducer

G

G extends Geometry

P

P extends GeoJsonProperties = GeoJsonProperties

参数

geojson

any GeoJSON object

Feature<G, P> | FeatureCollection<G, P> | Feature<GeometryCollection<Geometry>, P>

callback

(previousValue: Reducer, currentFeature: Feature<G, P>, featureIndex: number) => Reducer

a method that takes (previousValue, currentFeature, featureIndex)

initialValue?

Reducer

Value to use as the first argument to the first call of the callback.

返回

Reducer

The value that results from the reduction.

示例

var features = turf.featureCollection([
  turf.point([26, 37], {"foo": "bar"}),
  turf.point([36, 53], {"hello": "world"})
]);

turf.featureReduce(features, function (previousValue, currentFeature, featureIndex) {
  //=previousValue
  //=currentFeature
  //=featureIndex
  return currentFeature
});