如何解构嵌套GeoJSON对象以获取指定格式的数组？

实现方案 #

你可以通过数组遍历+对象/数组解构的方式快速完成格式转换，具体实现如下：

1. 解构实现（推荐） #

直接在map遍历的回调参数中完成字段解构，代码简洁易读：

// 你的原始GeoJSON对象
const originData = {"type":"FeatureCollection","name":"zentroide_bezirke_4326","crs":{"type":"name","properties":{"name":"urn:ogc:def:crs:OGC:1.3:CRS84"}},"features":[{"type":"Feature","properties":{"fid":2,"id":"BEZIRKSGRENZEOGD.10890","NAMEK":"Josefstadt","BEZNR":8,"BEZ_RZ":"VIII","NAMEK_NUM":"8., Josefstadt","NAMEK_RZ":"VIII. Josefstadt","NAMEG":"JOSEFSTADT","LABEL":"VIII.","BEZ":"08","DISTRICT_CODE":1080,"STATAUSTRIA_BEZ_CODE":908,"STATAUSTRIA_GEM_CODE":90801,"FLAECHE":1089945.694,"UMFANG":4170.3,"AKT_TIMESTAMP":"2021-09-13","SE_SDO_ROWID":10890,"SE_ANNO_CAD_DATA":null},"geometry":{"type":"Point","coordinates":[16.347822689187193,48.211029313540855]}},{"type":"Feature","properties":{"fid":3,"id":"BEZIRKSGRENZEOGD.10891","NAMEK":"Innere Stadt","BEZNR":1,"BEZ_RZ":"I","NAMEK_NUM":"1., Innere Stadt","NAMEK_RZ":"I. Innere Stadt","NAMEG":"INNERE STADT","LABEL":"I.","BEZ":"01","DISTRICT_CODE":1010,"STATAUSTRIA_BEZ_CODE":901,"STATAUSTRIA_GEM_CODE":90101,"FLAECHE":2868773.8207,"UMFANG":6972.75,"AKT_TIMESTAMP":"2021-09-13","SE_SDO_ROWID":10891,"SE_ANNO_CAD_DATA":null},"geometry":{"type":"Point","coordinates":[16.36939878396175,48.208360983479615]}}]}

const data = originData.features.map(({
  properties: { NAMEK },
  geometry: { coordinates: [lng, lat] }
}) => ({
  NAMEK,
  coordinates: { lat, lng }
}))

注意：GeoJSON规范中坐标数组顺序为[经度, 纬度]，所以提取时lat对应数组索引1的取值，lng对应索引0的取值，不要写反导致坐标偏移。

2. 普通取值实现 #

如果对解构语法不熟悉，也可以用常规的链式取值实现，逻辑更直观：

const data = originData.features.map(feature => {
  return {
    NAMEK: feature.properties.NAMEK,
    coordinates: {
      lat: feature.geometry.coordinates[1],
      lng: feature.geometry.coordinates[0]
    }
  }
})

两种方式性能差异可以忽略，解构写法的优势是减少重复的前缀代码，提取字段越多优势越明显。

内容的提问来源于stack exchange，提问作者Lenn