flatten累加(flattenReduce)

> npm install @turf/meta

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

接收任意 GeoJSON 对象(包括要素集)，遍历累加操作。功能类似 Array.reduce()

值得注意的是，如果是多要素集，做扁平处理再遍历，功能类似 Array.flat()

参数

参数	类型	描述
geojson	FeatureCollection|Feature|Geometry	任意 GeoJSON 对象
callback	Function	回调，参数依次是 previousValue、currentFeature、featureIndex、multiFeatureIndex
initialValue	(*)	初始值

返回

• The value that results from the reduction.

示例

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
});