ES6從數組過濾/減少對象

Question

給定

commentIdList = [2,3]
comments = { 1 : "a", 2: "b", 3: "c", 4: "d" }

需要輸出

filteredComments = [ {2:"b"} , {3:"c"} ]

我失敗的嘗試

const filteredComments = comments.filter((c)=> commentsIdList.map(comment=>c.id === comment))

Answer 1

使用Array.map()迭代commentIdList 。 通過鍵（ id ）從comments獲取值，並使用計算出的屬性名稱創建一個新對象：

 const commentIdList = [2,3]; const comments = { 1 : "a", 2: "b", 3: "c", 4: "d" } const filteredComments = commentIdList.map((id) => ({ [id]: comments[id] })); console.log(filteredComments); 

Answer 2

這是一種方法

commentIdList.map(commentId => ({ [commentId]: comments[commentId] })