javascript - 如何基于另一个对象数组创建一个对象数组？

Question

我有这个数组:

var arr1 = [
 {"user":"dan","liked":"yes","age":"22"},
 {"user":"sarah","liked":"no","age":"21"},
 {"user":"john","liked":"yes","age":"23"},
];

我想为该数组创建一个新的(子)数组，只包含用户的点赞。

所以它看起来像这样:

var arr2 = [
 {"dan":"yes"},
 {"sarah":"no"},
 {"john":"yes"},
];

我试过:

var arr2 =[];
for(var i in arr1){
  arr2.push({[i[user]]:i[liked]});
}

它需要一个调整， 想法？

Answer 1

使用array.map

var arr1 = [
 {"user":"dan","liked":"yes","age":"22"},
 {"user":"sarah","liked":"no","age":"21"},
 {"user":"john","liked":"yes","age":"23"},
];

var arr2 = arr1.map(v => ({ user: v.user, liked: v.liked }));

console.log(arr2);

对于您的更新，虽然可以使用 array.map 完成，但我建议您改用键值对结构。你需要 array.reduce .

  var arr1 = [
   {"user":"dan","liked":"yes","age":"22"},
   {"user":"sarah","liked":"no","age":"21"},
   {"user":"john","liked":"yes","age":"23"},
  ];

  var arr2 = arr1.reduce((c, v) => (c[v.user] = v.liked, c) , {});

  console.log(arr2);