使用 JavaScript 按键值过滤 JSON

Question

给定 users.json 中的对象数组：

{"key":"userSubscriptions","value":
[{"channel":"Netflix","user":"Bobby","region":"NA"},
[{"channel":"Netflix","user":"Bobby","region":"EU"},
[{"channel":"Netflix","user":"Jamie","region":"SEA"},
[{"channel":"Prime Video","user":"Bobby","region":"NA"}]}

如何进行过滤以使最终结果为

console.log(result); // Bobby, your region subscriptions are: Netflix: (NA, EU), Prime Video: (NA)

谢谢！

编辑：我尝试使用 .filter() 和 .map() 方法，但到目前为止没有运气

Answer 1

您的 JSON 数据无效。不过，我想我已根据您的意图对其进行了调整。

这会将数据分解为按用户的格式，并提供一个函数来为任何指定用户输出订阅和区域。

const jsonString = `{"key":"userSubscriptions","value":[{"channel":"Netflix","user":"Bobby","region":"NA"},{"channel":"Netflix","user":"Bobby","region":"EU"},{"channel":"Netflix","user":"Jamie","region":"SEA"},{"channel":"Prime Video","user":"Bobby","region":"NA"}]}`;

const obj = JSON.parse(jsonString);                                  // parse the data from a string into an object

const byUser = obj.value.reduce((acc, o) => {                        // reduce the "value" array to a single object
  if (!acc[o.user]) acc[o.user] = {};                                // create acc.userName if it does not exist
  if (acc[o.user][o.channel]) acc[o.user][o.channel].push(o.region); // if acc.userName.channelName has an array, add this region to it
  else acc[o.user][o.channel] = [o.region];                          // else create an array with this region in it
  return acc;                                                        // keep the created object for the next iteration
}, {});

function printForUser(userName) {                                    // create a function that takes a user's name
  const user = byUser[userName];                                     // take the user object from the byUser object
  return Object.keys(user).reduce((acc, k) => {                      // reduce the keys of the user object to one string
    return acc + ` ${k}: (${user[k].join(", ")}),`;                  // add on each subscription and regions
  }, `${userName}, your region subscriptions are:`).slice(0, -1);    // initialize the string and remove the last comma
}

console.log( printForUser("Bobby") );

Answer 2

你必须使用 lodash 来分组数据，然后映射数据

var data = {
                "key":"userSubscriptions",
                "value":
                [{"channel":"Netflix","user":"Bobby","region":"NA"},
                {"channel":"Netflix","user":"Bobby","region":"EU"},
                {"channel":"Netflix","user":"Jamie","region":"SEA"},
                {"channel":"Prime Video","user":"Bobby","region":"NA"}]
            }

            var users = _.chain(data.value)
                .groupBy("user").map((value, key) => ({ user: key, data: value })).value();

                users.forEach(element => {
                    console.log(element)

                    console.log(`${element.user}, your region subscriptions are: Netflix: ${element.data.map(c=>c.channel).join(',')}, Prime Video: ${element.data.map(c=>c.region).join(',')}`)
                });