JavaScript：如何从对象数组中获取新的值数组？

Question

这是我的API数据：

Home: {
  metrics: {
    aggregated_users_count: [
      {
        count: 1,
        joined_day: '2019-08-13'
      },
      {
        count: 2,
        joined_day: '2019-08-14'
      }    
    ]
  }
}

我想在'userCount'数组中分配'count'值，在'registeredDate'数组中分配'joined_day'。

例如：

const userCount = [1,2]

Answer 1

可以by mapping your API data实现两个数组，如下所示：

const Response = {
  Home: {
    metrics: {
      aggregated_users_count: [{
          count: 1,
          joined_day: '2019-08-13'
        },
        {
          count: 2,
          joined_day: '2019-08-14'
        }
      ]
    }
  }
};

const aggregatedUserData = Response.Home.metrics.aggregated_users_count;

/* Perform mapping to extract fields of each item to respective arrays */
const registeredDate = aggregatedUserData.map(({ joined_day }) => joined_day);
const userCount = aggregatedUserData.map(({ count }) => count);

console.log("registeredDate:", registeredDate);
console.log("userCount:", userCount);

Answer 2

const userCount = Home.metrics.aggregated_users_count.map((data) => data.count)