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Version: 7.3.0

lineReduce

描述​

🌐 Description

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

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

参数​

🌐 Parameters

名称类型描述
geojsonFeatureCollection<Lines> | Feature<Lines> | Lines | Feature<GeometryCollection> | GeometryCollectionobject
callback函数一个接收 (previousValue, currentLine, featureIndex, multiFeatureIndex, geometryIndex) 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 multiPoly = turf.multiPolygon([
  turf.polygon([
    [
      [12, 48],
      [2, 41],
      [24, 38],
      [12, 48],
    ],
    [
      [9, 44],
      [13, 41],
      [13, 45],
      [9, 44],
    ],
  ]),
  turf.polygon([
    [
      [5, 5],
      [0, 0],
      [2, 2],
      [4, 4],
      [5, 5],
    ],
  ]),
]);

turf.lineReduce(
  multiPoly,
  function (
    previousValue,
    currentLine,
    featureIndex,
    multiFeatureIndex,
    geometryIndex,
  ) {
    //=previousValue
    //=currentLine
    //=featureIndex
    //=multiFeatureIndex
    //=geometryIndex
    return currentLine;
  },
);

安装​

🌐 Installation

$ npm install @turf/meta

import { lineReduce } from "@turf/meta";
const result = lineReduce(...);
$ npm install @turf/turf

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