从 JavaScript 中嵌套的 Object 抓取特定键（属性）的最佳方法

Question

What is the best method to get specific keys (ie "longName") from nested objects with this structure:

const routes = {
   "14094": {
      "routeId": 14094,
      "shortName": "2",
      "longName": "Route 1"
   },
   "14095": {
      "routeId": 14095,
      "shortName": "7",
      "longName": "Route 2"
   },
   "14096": {
      "routeId": 14096,
      "shortName": "42",
      "longName": "Route 3"
   },
   "14097": {
      "routeId": 14097,
      "shortName": "57",
      "longName": "Route 4"
   },

I have tried to console.log(routes[1]), dot notation, and other methods but I am not having any success.

Answer 1

The structure here is an object of objects. So you can access the longName key-value pair in this manner: routes[14094].longName which should return Route 1 , based on the original data.

If you want to get all the longName values for each object, you can use a for loop like this:

for (const key in routes) {
   console.log(routes[key].longName)
   }

You need to first reference the object using the "outer" key (eg 14094), then you can use dot notation for the keys in the "inner" object.