javascript从数组中的所有对象中提取某些属性

Question

我有一组具有相同属性的对象.每个对象有大约一百个属性.我想在一个新的数组中只保留少数几个:

var dummyArray = [{ "att1": "something", "att2": "something", ..., "att100": "something"}, { "att1": "something", "att2": "something", ..., "att100": "something"}, ...];

如何过滤/映射/缩小...并提取有趣的键？

const newDummArray = dummyArray.map(function(item) { 
    delete item.att1; 
    delete item.att3; 
    delete item.att15;
    // ... (long list)
    return item; 
});

我怎么能只保留att20,att30,att70,att80为每个对象,并删除其余？

Answer 1

map 创建一个新数组，所以不需要删除任何东西，而是创建一个有趣的键数组并返回它

var dummyArray = [{
  "att1": "something",
  "att2": "something",
  "att20": "something",
  "att100": "something"
}, {
  "att1": "something",
  "att2": "something",
  "att20": "something",

  "att100": "something"
}];

let x = dummyArray.map((item) => {
  return {
    attr20: item.att20
  }

})

console.log(x)

Answer 2

我找到了最简单的方法来执行此 JSON.stringify()

JSON.stringify() 方法将 JavaScript 对象或值转换为 JSON 字符串，如果指定了替换函数，则可以选择替换值；如果指定了替换数组，则可以选择仅包含指定的属性。

    const odata = [
      { "id": "0001", "type": "donut", "name": "Cake", "ppu": 0.55 },
      { "id": "0002", "type": "ansd", "name": "EARK", "ppu": 0.67 }
    ];
    const outdata=JSON.stringify(odata,['id','type']);
    console.log(outdata);

Answer 3

使用对象解构获取属性,并使用速记属性名称生成新对象:

const dummyArray = [{ "att20": "att20", "att30": "att30", "att70": "att70", "att80": "att80"}, { "att20": "att20", "att30": "att30", "att70": "att70", "att80": "att80"}];

const result = dummyArray.map(({ att20, att30, att70, att80 }) => ({
  att20, 
  att30, 
  att70, 
  att80
}));

console.log(result);

Answer 4

将您想要保留的道具存储在一个数组中，然后为每个对象将想要的道具转移到一个新对象。

var dummyArray = [{ "att1": "something", "att2": "something", "att100": "something"}, { "att1": "something", "att2": "something", "att100": "something"}];

var propsToKeep = ["att1", "att100"];

var result = dummyArray.map(item => {
  const obj = {};
  for (const prop of propsToKeep) {
    obj[prop] = item[prop];
  }
  return obj;
})

console.log(result)