如何遍歷深度嵌套的 json 對象

Question

     var City ={
"City1": [{"name": "Place 1"},{"name": "Place 2"},{"name": "Place 3"}],
"City2":[{"name":"My Place 1"},{"name":"My Place 2"},{"name":"My Place 3"}],
"City3":[{"name":"My Place 1"},{"name":"My Place 2"},{"name":"My Place 3"}]
    };

我想使用 JavaScript 循環獲取第一個城市名稱，然后循環獲取其位置，然后獲取第二個城市及其位置，依此類推。

Answer 1

您可以使用for循環遍歷City對象的所有屬性：

for (var key in City) {
    if (City.hasOwnProperty(key)) {
        var values = City[key];
        // "key" will be City1, City2, ...
        // "values" will be the corresponding array through which
        // you can loop
    }
}

Answer 2

嘗試使用Object.keys() , Array.prototype.forEach()

 var City = { "City1": [{ "name": "Place 1" }, { "name": "Place 2" }, { "name": "Place 3" }], "City2": [{ "name": "My Place 1" }, { "name": "My Place 2" }, { "name": "My Place 3" }], "City3": [{ "name": "My Place 1" }, { "name": "My Place 2" }, { "name": "My Place 3" }] }; Object.keys(City).forEach(function(value, key) { console.log(value); City[value].forEach(function(v, k) { console.log(v.name) }) });

Answer 3

for (let key in City) {
    let value = City[key];
    console.log(key);
    for (i = 0; i <= value.length; i++) {
      console.log(value[i]);
    }
  }

Answer 4

function nestedLoop(obj) {
const res = {};
function recurse(obj, current) {
    for (const key in obj) {
        let value = obj[key];
        if(value != undefined) {
            if (value && typeof value === 'object') {
                recurse(value, key);
            } else {
                // Do your stuff here to var value
                res[key] = value;
            }
        }
    }
}
recurse(obj);
return res;

}