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Version: 7.3.0

propReduce

描述​

🌐 Description

将任何 GeoJSON 对象中的属性归约为单个值，类似于 Array.reduce 的工作方式。然而，在这种情况下，我们是惰性运行归约，所以不需要所有属性的数组。

🌐 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.

参数​

🌐 Parameters

名称类型描述
geojsonFeatureCollection | Feature | Geometry任何 GeoJSON 对象
callbackpropReduceCallback一种接受（previousValue, currentProperties, featureIndex）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.point([36, 53], { hello: "world" }),
]);

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

安装​

🌐 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(...);