从 geoJSON 到数组

Question

真正的问题是我似乎无法设置坐标内的值。

JSON 的开头看起来像这样。

{  
    "path":{  
        "type":"FeatureCollection",
        "features":[  
            {  
                "geometry":{  
                    "type":"LineString",
                    "coordinates":[  
                        [  
                            10.4048129700337,
                            63.416688738540316
                        ],
                        [  
                            10.404757623420094,
                            63.4167327334674
                        ]
                    ]
                },
                "type":"Feature",
                "id":85624,
                "properties":{  
                    "flags":[  

                    ],
                    "z":2.0,
                    "m":5.62957707088913e-06,
                    "target":85621,
                    "buildingId":43
                }
            }

当我运行它给了我代码时

"Uncaught TypeError: Cannot set property '0' of undefined" on remakeObj[i].coordinates[j][k] = coordinates[j][k];

现在已经解决了。我是这样解决的

parseToObjects: function (data) {
    var remakeObj = [];
    var features = data.path.features;
    for (var i in features) {
        remakeObj[i] = {
            flooring: "",
            meters: "",
            coordinates: []
        };

        var coordinates = features[i].geometry.coordinates;

        for (var j in coordinates) {
            remakeObj[i].coordinates[j] = [];
            for (var k in coordinates[j]) {

                remakeObj[i].coordinates[j][k] = coordinates[j][k];
                remakeObj[i].flooring = features[i].properties.z;
                remakeObj[i].meters = features[i].properties.m;

            }
        }

    }
    console.log(remakeObj);
    return remakeObj;
}

Answer 1

JavaScript 中的数组实际上是 hash tables（可以把它想象成包含值和键以便以某种方式访问它的桶）而不是序列号索引的数组。

虽然允许使用数字索引作为键，但数组也可以包含其他类型的键（string 类型等）。

因此，索引0不会return数组的第一个元素，而是存储myArray[0]的值元素，如果有的话（在你的情况下，没有任何这就是您收到错误的原因）。

您需要使用设置的键迭代数组，以便连续访问所有值：

for (var key in myArray) {
    var y = myArray[key]; //Index it like this, use it similarly.
}

更新：这是你可能做的（警告：未经测试的代码）：

for (var featuresKey in features) {
    remakeObj[featuresKey] = [features.length];
    var coordinates = features[featuresKey].geometry.coordinates;
    remakeObj[featuresKey].coordinates = new Array(coordinates.length);

    for (var coordinatesKey in coordinates) {

        for (var innerCoordinatesKey in coordinates[coordinatesKey]) {
            remakeObj[featuresKey].coordinates[coordinatesKey][innerCoordinatesKey] =
                coordinates[coordinatesKey][innerCoordinatesKey];
            remakeObj[featuresKey].flooring = features[featuresKey].properties.z;
            remakeObj[featuresKey].meters = features[featuresKey].properties.m;


        }

    }

}

从 geoJSON 到数组

From geoJSON to Array

javascript

arrays

json

multidimensional-array

geojson