起初：我知道，有很多這樣的問題，但答案沒有幫助。我是 JSON 的新手，并感謝每一個答案。
我有一個像這樣的 json 物件：
{
"version": 0.6,
"generator": "Overpass API 0.7.57 93a4d346",
"osm3s": {
"timestamp_osm_base": "2021-10-26T12:48:42Z",
"copyright": "The data included in this document is from www.openstreetmap.org. The data is made available under ODbL."
},
"elements": [
{
"type": "node",
"id": 58489979,
"lat": 52.5098189,
"lon": 13.4073729,
"tags": {
"addr:city": "Berlin",
"addr:country": "DE",
"addr:housenumber": "83",
"addr:postcode": "10179",
"addr:street": "Alte Jakobstra?e",
"addr:suburb": "Mitte",
"brand": "Netto Marken-Discount",
"brand:wikidata": "Q879858",
"brand:wikipedia": "de:Netto Marken-Discount",
"name": "Netto Marken-Discount",
"shop": "supermarket",
"website": "http://netto-online.de/",
"wheelchair": "no"
}
},
{
"type": "node",
"id": 269479009,
"lat": 52.5136840,
"lon": 13.4060088,
"tags": {
"addr:city": "Berlin",
"addr:country": "DE",
"addr:housenumber": "12",
"addr:postcode": "10179",
"addr:street": "Fischerinsel",
"addr:suburb": "Mitte",
"contact:website": "http://www.edeka.de",
"name": "Edeka Ungefroren",
"opening_hours": "Mo-Sa 07:00-21:00",
"shop": "supermarket",
"toilets:wheelchair": "yes",
"wheelchair": "yes"
}
}, ...
json 物件可以有數百個以 "type" : "node" 開頭的元素。現在我想訪問所有經緯度和名稱。有很多示例如何訪問元素，我知道但它們不起作用，例如這不起作用：
JSONObject jsonObj = new JSONObject(string);
jsonObj.getString("lat");
此外，我有數百個元素，我想訪問所有 lats、所有 lons 和所有名稱。我怎么做？我看到的大多數示例都是針對簡單的 json 物件，還是我只是理解錯了？
uj5u.com熱心網友回復：
您首先需要將“元素”屬性作為 JSONArray 獲取。然后你可以檢索 JSONObject 持有 lat 如下：
JSONObject jsonObj = new JSONObject(string);
JSONArray resultArray = jsonObj.getJSONArray("elements");
for (int i = 0; i < resultArray.length(); i ) {
JSONObject item = resultArray.getJSONObject(i);
// Now you can retrieve the lat
double lat = item.getDouble("lat"); // Not getString("lat") because lat is a number, not a string
...
}
轉載請註明出處，本文鏈接：https://www.uj5u.com/shujuku/337382.html
上一篇：在JS/TS中有效地將元素推送到Float32Array的每第四位
下一篇：在異步函式中使用遞回