Question

注意：有人指出已经提出了一些可能的解决方案here。但是，.map 完全我正在寻找的内容并没有出现在那个全面的帖子中。 Thomas的回答包括我的用例。

使用javascript，如何为GeoJSON文件中的每个要素创建一个表示任意属性值的值数组？我意识到我在这里失败了JSON 101，但我怎么能创建它：

['caiparinha','caucasian','margarita']

从这个？

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "name": "brasil",
        "beverage": "caiparinha"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          -56.953125,
          -8.754794702435605
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "name": "russia",
        "beverage": "caucasian"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          39.0234375,
          57.136239319177434
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "name": "mexico",
        "beverage": "margarita"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          -105.1171875,
          25.165173368663954
        ]
      }
    }
  ]
}

如果源是CSV，那么就像从属性中选择/解析单个列一样简单，但是使用GeoJSON，属性（即列）是如此深层嵌套，以至于我没有运气{ {1}}，我想避免循环，但此时我会采取任何措施。

上下文是我希望能够从example为我映射的要素附加的每个“变量”中提取分布信息。

Answer 1

尝试以下内容

var geojson = {
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "name": "brasil",
        "beverage": "caiparinha"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          -56.953125,
          -8.754794702435605
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "name": "russia",
        "beverage": "caucasian"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          39.0234375,
          57.136239319177434
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "name": "mexico",
        "beverage": "margarita"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          -105.1171875,
          25.165173368663954
        ]
      }
    }
  ]
};

var expected_result = geojson.features.map(function (el) {
  return el.properties.beverage;
});

console.log(expected_result);

如果您的GeoJSON来自Ajax调用，那么它首先是一个字符串，juste使用JSON.parse(yourGeoJSON)

如何从单个GeoJSON属性创建值数组？

1 个答案: