Question

嗨，我有这个对象，我想用forEach遍历这个对象，但是我不能，如何将它转换成数组？对不起，很抱歉，但这是一个json对象吗？

{
  file0: {
    fieldName: 'file0',
    originalFilename: '4.png',
  },
  file1: {
    fieldName: 'file1',
    originalFilename: '1.jpg',
  },
  file2: {
    fieldName: 'file2',
    originalFilename: '2.jpg',
  },
  file3: {
    fieldName: 'file3',
    originalFilename: '3.png',
  }
}

该数组将如下所示：

[
{},
{},
{},
{}
]

Answer 1

您需要其中之一？

仅带有对象的对象或带有对象AND键的对象？

const obj = {
  file0: {
    fieldName: 'file0',
    originalFilename: '4.png',
  },
  file1: {
    fieldName: 'file1',
    originalFilename: '1.jpg',
  },
  file2: {
    fieldName: 'file2',
    originalFilename: '2.jpg',
  },
  file3: {
    fieldName: 'file3',
    originalFilename: '3.png',
  }
}

// fast
const arr1 = Object.values(obj).slice(0); // see below why I slice
console.log(arr1);

// alternative using map: 

const arr2 = Object.keys(obj).map(key => obj[key]);
console.log(arr2);

// include the key:

const arr3 = Object.keys(obj).map(key => ({ [key]: obj[key] }));
console.log(arr3);

// Taking the Object.values directly, will POINT to the original object:
const arr4 = Object.values(obj);
arr4[0].fieldName = "XXX"
console.log(obj);

Answer 2

您只需使用map()即可获得所需的结果，如下所示：

const obj = {
  file0: {
    fieldName: 'file0',
    originalFilename: '4.png',
  },
  file1: {
    fieldName: 'file1',
    originalFilename: '1.jpg',
  },
  file2: {
    fieldName: 'file2',
    originalFilename: '2.jpg',
  },
  file3: {
    fieldName: 'file3',
    originalFilename: '3.png',
  }
}

const arr = Object.keys(obj).map(key => obj[key])

并获得以下结果：

[
{fieldName: "file0", originalFilename: "4.png"},
{fieldName: "file1", originalFilename: "1.jpg"},
{fieldName: "file2", originalFilename: "2.jpg"},
{fieldName: "file3", originalFilename: "3.png"}
]

如何将该对象转换为数组？

2 个答案: