# propReduce
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.
将任何GeoJSON对象中的属性减少为单个值,类似于Array.reduce
。但是,在本例中,我们延迟地运行缩减,因此没有必要使用所有属性的数组。
> npm install @turf/meta
参数
参数 | 类型 | 描述 |
---|---|---|
geojson | (FeatureCollection|Feature) | 任何 GeoJSON 对象 |
callback | Function | 回调函数 (previousValue, currentProperties, featureIndex) |
initialValue | (*) | 回调函数第一个参数初始值 |
返回
- 简化的结果值。
示例
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
});
← propEach segmentEach →