Javascript 遍历对象数组并返回一个对象，该对象仅包含其值已更改的键

Question

我有一个对象数组，需要遍历并检查对象的键是否具有不同的值。如果是这样，请返回此 key 。

const arrayOfObjects = [
  { item: { first_name: "Joe", last_name: "Dow", age: 15 } },
  { item: { first_name: "Joe", last_name: "d", age: 15 } },
  { item: { first_name: "Joe", last_name: "Dow", age: 20 } }
];

预期结果应该是

const result = {
  last_name: true,
  age: true
}

PS:每个对象总是有相同数量的键

Answer 1

您可以遍历 arrayOfObjects。检查当前 item 的键与之前对象的 item 相比是否具有不同的值。如果是，请在 result

中将该键设置为 true

const arrayOfObjects = [{ item: { first_name: "Joe", last_name: "Dow", age: 15 } }, { item: { first_name: "Joe", last_name: "d", age: 15 } }, { item: { first_name: "Joe", last_name: "Dow", age: 20 } }];
const result = {};

arrayOfObjects.forEach(({ item }, i, arr) => {
  if (i === 0) return; // skip the first item
  
  const prev = arr[i - 1].item; // get the previous item
  for (const key in item) {
    if (item[key] !== prev[key])
      result[key] = true
  }
})

console.log(result)