Question

我有一个JavaScript对象，其中一个属性是一个数组。我想修改该对象以创建几乎相同的对象，除了一个属性是String之外。

类似join方法可用于将数组更改为字符串（例如console.log(elements.join('-'))）。

但是如何创建一个与旧对象相同但具有一个不同属性（即字符串而不是数组）的新对象？

例如，我有一个对象carOriginal：

{
  "make": "Ford",
  "model": "F150",
  "features": [
    "windows",
    "seatbelts"
  ]
}

...，然后我要创建这个对象carNew：

{
  "make": "Chevy",
  "model": "Tahoe",
  "features": "windows,seatbelts"
}

Answer 1

如果使用ES6，则可以分解原始文件并添加新功能值：

const data = {
  "make": "Ford",
  "model": "F150",
  "features": [
    "windows",
    "seatbelts"
  ]
}


const other = {...data, features: data.features.join()}

console.log(other)

Answer 2

尝试一下：

const obj = {
  "make": "3",
  "model": "2019-07-17",
  "features": [
    "windows",
    "seatbelts"
  ]
}

const result  =  Object.assign({},obj, {features: obj.features.join()});
console.log(result);

Answer 3

您可以使用object rest and spread syntax将其余的密钥收集到一个单独的浅表副本中，修改后的属性将分配给该浅表副本：

const carOriginal = {
  "make": "Ford",
  "model": "F150",
  "features": [
    "windows",
    "seatbelts"
  ]
};

function transform ({ features, ...keys }) {
  return { ...keys, features: features.join() };
}

const carNew = transform(carOriginal);

console.log(carNew);

Answer 4

如果您不知道属性的名称，则必须检查每个值以查看其是否为数组：

function subJoin(obj) {
    for (let prop in obj) {
        if (obj.hasOwnProperty(prop)) {
            if (Array.isArray(obj[prop])) {
                obj[prop] = obj[prop].join(',');
            }
        }
    }
    return obj;
}


let input = {
    "make": "Ford",
    "model": "F150",
    "features": [
       "windows",
       "seatbelts"
    ]
}

let output = subJoin(input);
console.log(output); /// -->  { "make": "Chevy", "model": "Tahoe", "features": "windows,seatbelts" }

将JavaScript对象属性从数组修改为字符串

4 个答案: