propReduce

Description

Reduce properties in any GeoJSON object into a single value, similar to how Array.reduce works. However, in this case we lazily run the reduction, so an array of all properties is unnecessary.

Parameters

Name	Type	Description
geojson	FeatureCollection | Feature | Geometry	any GeoJSON object
callback	propReduceCallback	a method that takes (previousValue, currentProperties, featureIndex)
initialValue?	Reducer	Value to use as the first argument to the first call of the callback.

Returns

Reducer The value that results from the reduction.

Examples

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

turf.propReduce(
  features,
  function (previousValue, currentProperties, featureIndex) {
    //=previousValue
    //=currentProperties
    //=featureIndex
    return currentProperties;
  },
);

Installation

$ npm install @turf/meta

import { propReduce } from "@turf/meta";
const result = propReduce(...);

$ npm install @turf/turf

import * as turf from "@turf/turf";
const result = turf.propReduce(...);