Question

我正在使用leafletjs在openstretmap上显示一些多边形。

我有一个外部数据资源，它为我提供了多边形的坐标。不幸的是，这个数组的坐标顺序错误。

实施例：我明白了：

[[10.5254913,52.2734311]，[10.5258872,52.2734632]]

我需要：

[[52.2734311,10.5254913]，[52.2734632,10.5258872]]

所以我给自己写了一个小函数，它遍历数组并反转条目：

var polCoords = [];
$.each(value.polygon[0], function(key,value){
polCoords[key] = [value[1],value[0]]; 
});

这很好用。但现在我发现多边形的一些数组是多维的！所以我有一个像这样的数组：

[[[10.5261828,52.2726556],[10.5263222,52.2726767],[10.5263578,52.2726821],[10.5263637,52.2726677],[10.5263738,52.2726428],[10.5264042,52.2725678],[10.526186,52.2725346],[10.5261395,52.272649],[10.5261828,52.2726556]],[[10.5261828,52.2726556],[10.5261713,52.2726821],[10.5261621,52.2727047],[10.5259248,52.2726687],[10.5257879,52.2726479],[10.5257435,52.2727573],[10.5258014,52.2727661],[10.5257967,52.2727777],[10.5260173,52.2728113],[10.5261107,52.2728254],[10.5260641,52.2729403],[10.5259711,52.2729262],[10.5259526,52.2729234],[10.5258101,52.2732746],[10.5258697,52.2732837],[10.5260636,52.2733132],[10.5261371,52.2733243],[10.5262746,52.2729854],[10.5262888,52.2729876],[10.526312,52.2729304],[10.5262636,52.2729231],[10.5262239,52.272917],[10.5263222,52.2726767],[10.5261828,52.2726556]],[[10.5260636,52.2733132],[10.5260595,52.2733365],[10.5260575,52.2733486],[10.5258607,52.2733326],[10.5258631,52.2733195],[10.5258697,52.2732837],[10.5260636,52.2733132]]]

其中似乎包含多个多边形。

如何反转此多维数组的每个条目？

Answer 1

假设array是您的数据，请尝试以下内容：

var reversed = array.map(function reverse(item) {
    return Array.isArray(item) && Array.isArray(item[0]) 
               ? item.map(reverse) 
               : item.reverse();
});

这是vanilla JavaScript。我认为在jquery中会是这样的：

var reversed = $.map(array, function reverse(item) {
    return $.isArray(item) && $.isArray(item[0])
               ? $.map(item, reverse)
               : item.reverse();
});

我没有尝试，但应该同时适用它们。让我知道。

Answer 2

array=[[1,2,3],[4,5,6],[7,8,9]]

reverse_2D_array=array.map(row=>row.reverse()).reverse()

reverse_2D_array=[[9,8,7],[6,5,4],[3,2,1]]

<块引用>

注意：这个方法会改变原来的数组。

Answer 3

<script type="text/javascript">
        //given array
        var arr = [
                    [
                        [10.5261828, 52.2726556],
                        [10.5263222, 52.2726767],
                        [10.5263578, 52.2726821],
                        [10.5263637, 52.2726677],
                        [10.5263738, 52.2726428],
                        [10.5264042, 52.2725678],
                        [10.526186, 52.2725346],
                        [10.5261395, 52.272649],
                        [10.5261828, 52.2726556]
                    ],
                    [
                        [10.5261828, 52.2726556],
                        [10.5261713, 52.2726821],
                        [10.5261621, 52.2727047],
                        [10.5259248, 52.2726687],
                        [10.5257879, 52.2726479],
                        [10.5257435, 52.2727573],
                        [10.5258014, 52.2727661],
                        [10.5257967, 52.2727777],
                        [10.5260173, 52.2728113],
                        [10.5261107, 52.2728254],
                        [10.5260641, 52.2729403],
                        [10.5259711, 52.2729262],
                        [10.5259526, 52.2729234],
                        [10.5258101, 52.2732746],
                        [10.5258697, 52.2732837],
                        [10.5260636, 52.2733132],
                        [10.5261371, 52.2733243],
                        [10.5262746, 52.2729854],
                        [10.5262888, 52.2729876],
                        [10.526312, 52.2729304],
                        [10.5262636, 52.2729231],
                        [10.5262239, 52.272917],
                        [10.5263222, 52.2726767],
                        [10.5261828, 52.2726556]
                    ],
                    [
                        [10.5260636, 52.2733132],
                        [10.5260595, 52.2733365],
                        [10.5260575, 52.2733486],
                        [10.5258607, 52.2733326],
                        [10.5258631, 52.2733195],
                        [10.5258697, 52.2732837],
                        [10.5260636, 52.2733132]
                    ]
                ];        

        var arrModified = new Array();
        var intDepth = 0;

        //array depth calculation
        function arrayDepth(arr) {
            for(item in arr) {
                if (Object.prototype.toString.call(arr) === '[object Array]') {
                    intDepth++;
                    arrayDepth(item);
                }
            }
        }
        arrayDepth(arr);

        //for depth 1
        if (intDepth == 1) {            
                arrModified = arr.reverse();
        }

        //for depth 2
        if (intDepth == 2) {
            for (item in arr) {
                arrModified[item] = arr[item].reverse();
            }
        }

        //for depth 3
        if (intDepth == 3) {
            for (i in arr) {
                var arrTemp = arr[i];
                var arrTemp1 = new Array();
                for (j in arrTemp) {
                    arrTemp1[j] = arrTemp[j].reverse();
                }
                arrModified[i] = arrTemp1;                
            }            
        }

        //so on for other depths
        //arrModified is the required array

    </script>

在javascript中反转（多维）数组中的条目

3 个答案: