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	any GeoJSON object
callback	Function	a method that takes (previousValue, currentProperties, featureIndex)
initialValue?	*	Value to use as the first argument to the first call of the callback.

Returns

* 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(...);