如何使用array.map方法從數組數組返回對象數組？

Question

我使用 React 並且在 Redux Persist 減速器中有這個數組：

const data = [["2020-09-14","15:00","60","Info","April Tucker","Other","yes"],
["2020-09-14","2:00","50","Text","April Tucker","Other","yes"]]

我想用數據數組中的一些值返回一個新的對象數組（對於數組中的每個數組）。 它應該是什么樣子的示例：

let events = [{ title: data[0][3], date: data[0][0] },{ title: data[1][3], date: data[1][0]}] 

我嘗試使用 array.map 方法：

 let events [
    data.map((index) => ({
      title: data[index][3],
      date: data[index][0],
    })),
  ]

這不像我預期的那樣工作。 如何正確地做到這一點？

Answer 1

.map函數為您提供數組的每一項作為回調函數中的參數。

像這樣使用它：

 const data = [ ["2020-09-14", "15:00", "60", "Info", "April Tucker", "Other", "yes"], ["2020-09-14", "2:00", "50", "Text", "April Tucker", "Other", "yes"] ] let events = data.map(item => ({ title: item[3], date: item[0], })) console.log(events)

Answer 2

map函數上的回調將實際數組項作為第一個參數，將索引作為第二個參數，而您的函數將index作為第一個參數。

此外，您將地圖操作的結果放在方括號[ ] 。 map 生成的數組將作為新數組中的第一個元素放置，而您可能不希望那樣

let events = data.map(arr => ({
  title: arr[3],
  date: arr[0],
})

Answer 3

使用解構和速記屬性名稱，一二三很容易

 const data = [["2020-09-14","15:00","60","Info","April Tucker","Other","yes"], ["2020-09-14","2:00","50","Text","April Tucker","Other","yes"]] let events = data.map(([date,,,title]) => ({title, date}) ) console.log(events)