在導入時從json創建鍵值對

我是jquery的新手 - 我有一個有效的geojson文件，它的features我想訪問並轉換爲鍵值對的對象。我的目標是隻使用properties.cat作爲關鍵字，而properties.name作爲值（所有其他數據可以忽略）。下面是一個示例：在導入時從json創建鍵值對

{ 
"type": "FeatureCollection", 
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:EPSG::3857" } }, 
"features": [ 
{ "type": "Feature", "properties": { "cat": "A", "name": "Aberdeen"}, "geometry": { "type": "Point", "coordinates": [ 16.37208, 48.20849 ] } }, 
{ "type": "Feature", "properties": { "cat": "B", "name": "Berlin"}, "geometry": { "type": "Point", "coordinates": [ 4.3517103, 50.8503396 ] } }, 
{ "type": "Feature", "properties": { "cat": "C", "name": "Copenhagen"}, "geometry": { "type": "Point", "coordinates": [ 4.3517103, 50.8503396 ] } }, 
{ "type": "Feature", "properties": { "cat": "D", "name": "Dublin" }, "geometry": { "type": "Point", "coordinates": [ 12.56553, 55.67594 ] } }, 
{ "type": "Feature", "properties": { "cat": "E", "name": "Edinburgh"}, "geometry": { "type": "Point", "coordinates": [ -3.7037902, 40.4167754 ] } } 
] 
} 


    $.getJSON("sample.geojson", function(json) { 

    console.log(json.features[0].properties.cat); 

     });

正如以下指出的那樣，features是一個數組。怎會直接從每個創建鍵值對的對象在JSON功能特性使其具有以下輸出：

{A : Aberdeen, B: Berlin, C: Copenhagen, D: Dublin, E: Edinburgh}

來源

2017-06-04 the_darkside

你嘗試了JSON解析可變它之前登錄到控制檯？ – Botimoo

var obj是什麼？ – RohitS

我編輯了這個問題。請重新打開 –

爲$.getJson方法回調函數響應已經自動解析。

另外，特徵對象是一個數組。使用此：

console.log(json.features[0].properties.cat);

爲了使鍵 - 值對，您可以使用reduce方法，它接受應用到每個項目一個callback提供的方法。

var json= { 
 
     "type": "FeatureCollection", 
 
     "crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:EPSG::3857" } }, 
 
     "features": [ 
 
     { "type": "Feature", "properties": { "cat": "A", "name": "Aberdeen"}, "geometry": { "type": "Point", "coordinates": [ 16.37208, 48.20849 ] } }, 
 
     { "type": "Feature", "properties": { "cat": "B", "name": "Berlin"}, "geometry": { "type": "Point", "coordinates": [ 4.3517103, 50.8503396 ] } }, 
 
     { "type": "Feature", "properties": { "cat": "C", "name": "Copenhagen"}, "geometry": { "type": "Point", "coordinates": [ 4.3517103, 50.8503396 ] } }, 
 
     { "type": "Feature", "properties": { "cat": "D", "name": "Dublin" }, "geometry": { "type": "Point", "coordinates": [ 12.56553, 55.67594 ] } }, 
 
     { "type": "Feature", "properties": { "cat": "E", "name": "Edinburgh"}, "geometry": { "type": "Point", "coordinates": [ -3.7037902, 40.4167754 ] } } 
 
     ] 
 
} 
 
var obj=json.features.reduce(function(obj,item){ 
 
    obj[item.properties.cat]=item.properties.name; 
 
    return obj; 
 
},{}); 
 
console.log(obj);

來源

2017-06-04 19:21:28

謝謝，我編輯了我的問題 –

@the_darkside，看看更新的答案。 –

謝謝@Alexandru，但是當我用getJSON包裝它時，它不起作用：'$ .getJSON（「sample.geojson」，function（json）{varilla = {}; json.features.reduce（function（obj，項）{ OBJ [item.properties.cat] = item.properties.name; 返回物鏡; }，{}）; 的console.log（OBJ） }）;' –

在導入時從json創建鍵值對

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