Question

我有以下对象

var obj1 = 
[
    {
        "id": 1373744172,
        "name": "Run",
        "distance": 6051.8,
        "date": "2018-01-24T16:43:09Z",
    },
    {
        "id": 1370355715,
        "name": "Swim",
        "distance": 1043,
        "date": "2018-01-22T21:10:28Z",
    }
]

var dest = 
[
    {title: "Placeholder", body: "1900-01-01T00:00:00Z"}
]

我试图基于obj1覆盖dest，所以我最终应该用

[
    {title: "Run", body: "2018-01-24T16:43:09Z"},
    {title: "Swim", body: "2018-01-22T21:10:28Z"}
]

我看过Object.assign和for-in循环，但我还没有找到正确的方法。例如

＆＃13;

var obj1 = 
[
    {
        "id": 1373744172,
        "name": "Run",
        "distance": 6051.8,
        "date": "2018-01-24T16:43:09Z",
    },
    {
        "id": 1370355715,
        "name": "Swim",
        "distance": 1043,
        "date": "2018-01-22T21:10:28Z",
    }
]

var dest = 
[
    {title: "Placeholder", body: "1900-01-01T00:00:00Z"}
]

Object.assign(dest, {title: obj1.name, body: obj1.date});

console.log(JSON.stringify(dest));

＆＃13;

我确定之前一定要问过并回答过，但我似乎没有用正确的条款进行搜索！

Answer 1

您不需要Object.assign，使用array.prototype.map转换数组的每个元素：

var obj1 = 
[
    {
        "id": 1373744172,
        "name": "Run",
        "distance": 6051.8,
        "date": "2018-01-24T16:43:09Z",
    },
    {
        "id": 1370355715,
        "name": "Swim",
        "distance": 1043,
        "date": "2018-01-22T21:10:28Z",
    }
];

var dest = obj1.map(e => ({title: e.name , body: e.date}));

console.log(dest);

Answer 2

要保持相同的数组实例（如注释中所述）Array.splice可以与Array.map结合使用以转换新元素。但是splice将新元素作为附加参数，因此需要对调用splice有点聪明：

let args = [0, dest.length].concat(obj1.map(e=>({title: e.name, body: e.date})));
dest.splice.apply(dest, args);

将特定数组元素复制到现有对象（覆盖）

2 个答案: