Question

我正在从geojson文件中获取数据，我想展平数组中的数组以能够在材料表中显示此数据。

我有以下代码：

          const geoListData: Array<any> = [];
          const features = geoData.features; // feature array
          const latIdx = 0;
          const lonIdx = 1;

          // iterate over each feature
          features.forEach((feature: any) => {
            const geoListArray: any = [];

            // build up GeoListEntry
            const geoListEntry: GeoListEntry = {
              name: feature.properties.name,
              category: feature.properties.category,
              lat: feature.geometry.coordinates[latIdx],
              lon: feature.geometry.coordinates[lonIdx],
              prio: feature.properties.prio
            };

            geoListArray.push(geoListEntry);

            // get values from geojson
            feature.properties.values.forEach((element: any) => {
              const valuesEntry: any = {
                [element.name]: element.value
              };
              geoListArray.push(valuesEntry);
            });

            this.logger.debug(`geoListArray: ${JSON.stringify(geoListArray)}`);

            geoListData.push(geoListArray);
          });

      return geoListData;
    }));

我的记录器输出如下：

[{"name":"90","category":"Arc 12 month","lat":7.613333333,"lon":47.555555,"prio":0},{"bearing":12345},{"intensity_mean":0},{"intensity_min":0},{"intensity_max":0}]

但是我想要这样的东西：

[{"name":"90","category":"Arc 12 month","lat":7.613333333,"lon":47.555555,"prio":0,"bearing":12345,"intensity_mean":0,"intensity_min":0,"intensity_max":0}]

我已经接近了，但是我找不到解决方法。

你有什么主意吗？

Answer 1

与其将属性推送到array，而是直接将属性添加到object

// iterate over each feature
features.forEach((feature: any) => {
  const geoListArray: any = [];

  // build up GeoListEntry
  const geoListEntry: GeoListEntry = {
    name: feature.properties.name,
    category: feature.properties.category,
    lat: feature.geometry.coordinates[latIdx],
    lon: feature.geometry.coordinates[lonIdx],
    prio: feature.properties.prio
  };

  // get values from geojson
  feature.properties.values.forEach((element: any) => {
    geoListEntry[element.name] = element.value
  });

  geoListArray.push(geoListEntry);

  this.logger.debug(`geoListArray: ${JSON.stringify(geoListArray)}`);

  geoListData.push(geoListArray);
});

Answer 2

从技术上讲，它不是数组的数组，而是要合并的对象的集合：

const data = [
  { id: 1 },
  { lat: 10 },
  { lng: 20 },
];

console.log(data.reduce((p, n) => ({...p, ...n}), {}));

只要您真的想要展平功能，就可以了：

const data = [
  [{ id: 1 }],
  [{ lat: 10 }],
  [{ lng: 20 }],
];

console.log(Array.prototype.concat.apply([], data));

将两者混在一起？

const data = [
  [{ id: 1 }],
  [{ lat: 10 }],
  [{ lng: 20 }],
];

console.log((Array.prototype.concat.apply([], data)).reduce((p, n) => ({...p, ...n}), {}));

在数组内展平数组

2 个答案: