flattenReduce

描述

🌐 Description

减少任何 GeoJSON 对象中的扁平要素，类似于 Array.reduce()。

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

参数

🌐 Parameters

名称	类型	描述
geojson	FeatureCollection | Feature | GeometryObject | GeometryCollection | Feature<GeometryCollection>	任何 GeoJSON 对象
callback	flattenReduceCallback	一种接收（previousValue，currentFeature，featureIndex，multiFeatureIndex）的方法
initialValue?	归约器	作为回调的第一次调用的第一个参数使用的值。

返回

🌐 Returns

归约器 归约操作的结果值。

示例

🌐 Examples

var features = turf.featureCollection([
  turf.point([26, 37], { foo: "bar" }),
  turf.multiPoint(
    [
      [40, 30],
      [36, 53],
    ],
    { hello: "world" },
  ),
]);

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

安装

🌐 Installation

$ npm install @turf/meta

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

$ npm install @turf/turf

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