通过仅选择其属性的一部分从另一个对象数组构建对象数组答案

【问题标题】：Build an array of objects from another array of object by selecting just a part of its properties通过仅选择其属性的一部分从另一个对象数组构建对象数组
【发布时间】：2021-05-14 09:34:40
【问题描述】：

具有以下输入数组：

const initialArray = [{name: 'john', age: 12, height: 178, likes: 'music'},
                      {name: 'mike', age: 22, height: 181, likes: 'sport'},
                      {name: 'anna', age: 18, height: 175, likes: 'sleep'},
                      {name: 'paul', age: 24, height: 170, likes: 'drink'}
                     ];

我想构建一个新的对象数组，其中只包含一些属性，例如，只包含 name 和 height。结果是：

result = [{name: 'john', height: 178},
          {name: 'mike', height: 181},
          {name: 'anna', height: 175},
          {name: 'paul', height: 170}
         ];

尝试使用map，但可能有问题：

  const result = initialArray.map((a) => {
    a.name, a.height
  });

【问题讨论】：

试试这个initialArray.map((a) => ({name: a.name, height: a.height}));

标签： javascript arrays object ecmascript-6

【解决方案1】：

您应该在{} 中使用return 关键字，或者使用()（括号）扭曲代码。

您可以尝试使用Destructuring assignment，它允许您在结果对象中指定所需的属性名称：

const initialArray = [
  {name: 'john', age: 12, height: 178, likes: 'music'},
  {name: 'mike', age: 22, height: 181, likes: 'sport'},
  {name: 'anna', age: 18, height: 175, likes: 'sleep'},
  {name: 'paul', age: 24, height: 170, likes: 'drink'}
];
const result = initialArray.map(({name, height}) => ({name,height}));
console.log(result);

【讨论】：

【解决方案2】：

你应该像下面这样返回对象。

const result = initialArray.map((a) => {
  return {name:a.name, height:a.height}
});

【讨论】：

【解决方案3】：

您可以使用map、reduce 或for..of 循环轻松实现此目的

1) 使用地图

const initialArray = [
  { name: "john", age: 12, height: 178, likes: "music" },
  { name: "mike", age: 22, height: 181, likes: "sport" },
  { name: "anna", age: 18, height: 175, likes: "sleep" },
  { name: "paul", age: 24, height: 170, likes: "drink" },
];

const result = initialArray.map(({ name, height }) => ({ name, height }));
console.log(result);

2) 使用reduce

const initialArray = [
  { name: "john", age: 12, height: 178, likes: "music" },
  { name: "mike", age: 22, height: 181, likes: "sport" },
  { name: "anna", age: 18, height: 175, likes: "sleep" },
  { name: "paul", age: 24, height: 170, likes: "drink" },
];

const result = initialArray.reduce((acc, { name, height }) => {
  acc.push({ name, height });
  return acc;
}, []);
console.log(result);

3) 使用 for..of 循环

const initialArray = [
  { name: "john", age: 12, height: 178, likes: "music" },
  { name: "mike", age: 22, height: 181, likes: "sport" },
  { name: "anna", age: 18, height: 175, likes: "sleep" },
  { name: "paul", age: 24, height: 170, likes: "drink" },
];

const result = [];
for (let { name, height } of initialArray) {
  result.push({ name, height });
}
console.log(result);

【讨论】：

【解决方案4】：

另一种方法是使用 lodash 的选择（如果您需要动态解析属性的名称）或 ramda's pick 方法正是这样做的

const result = initialArray.map(R.pick(['name', 'height']));

【讨论】：