基于相同的键和值合并两个对象数组

Question

我有一个看起来像这样的数组：

[
    {
        like_id: 1, 
        likes: 1,
        post_id: 1,
        type: "feed_post_likes",
        _id: "b51771798ed01795cb8a17b028000329"
    }, 
    {
        post_id: 1,
        created_date: "2021-03-10T10:54:35.264Z",
        post_message: "Happy",
        post_pic: "",
        post_type: "post"
    }
]

我需要根据 post_id 合并这些数组并得到这个：

[
    {
        like_id: 1,
        likes: 1,
        post_id: 1,
        type: "feed_post_likes",
        _id: "b51771798ed01795cb8a17b028000329",
        created_date: "2021-03-10T10:54:35.264Z",
        post_message: "Happy",
        post_pic: "",
        post_type: "post"
    }
]

Answer 1

您可以使用数组减少方法执行以下操作，

 arr = [ { like_id: 1, likes: 1, post_id: 1, type: "feed_post_likes", _id: "b51771798ed01795cb8a17b028000329" }, { post_id: 1, created_date: "2021-03-10T10:54:35.264Z", post_message: "Happy", post_pic: "", post_type: "post" } ]; ret = arr.reduce((prev, curr) => { const idx = prev.findIndex(item => item.post_id === curr.post_id); if(idx > -1) { prev[idx] = {...prev[idx], ...curr}; } else { prev.push(curr); } return prev; }, []) console.log(ret);

Answer 2

这是我提出的一个解决方案：

 const arrayTest = [ {like_id: 1, likes: 1, post_id: 1, type: "feed_post_likes", _id: "b51771798ed01795cb8a17b028000329"}, {post_id: 1, created_date: "2021-03-10T10:54:35.264Z", post_message: "Happy", post_pic: "", post_type: "post"} ] const result = arrayTest.reduce((acc, curr) => { const hasIdAlready = acc.some(e => e.post_id === curr.post_id); if (hasIdAlready) { return acc } const foundMatchingElems = arrayTest.filter(e => e.post_id === curr.post_id) const mergedObjects = foundMatchingElems.reduce((obj, e) => ({...obj, ...e}), {}) return [...acc, mergedObjects] }, []) console.log(result)

Answer 3

您可以使用Array.prototype.reduce合并具有相同post_id的对象，然后使用Object.values获取合并对象的数组。

 const items = [ { like_id: 1, likes: 1, post_id: 1, type: 'feed_post_likes', _id: 'b51771798ed01795cb8a17b028000329' }, { post_id: 1, created_date: '2021-03-10T10:54:35.264Z', post_message: 'Happy', post_pic: '', post_type: 'post' } ] const result = items.reduce((acc, item) => ({...acc, [item.post_id]: {...acc[item.post_id] || {}, ...item } }), {}) console.log(Object.values(result))

Answer 4

您可以遍历存储已处理的每个post_id的对象数组，对于尚未处理的对象，您可以使用array.filter()返回具有给定post_id的对象数组，然后返回array.reduce()使用Object.assign()将所有对象合并为一个：

 var arr = [ { like_id: 1, likes: 1, post_id: 1, type: "feed_post_likes", _id: "b51771798ed01795cb8a17b028000329" }, { post_id: 1, created_date: "2021-03-10T10:54:35.264Z", post_message: "Happy", post_pic: "", post_type: "post" } ]; let processed = []; let result = []; for(obj in arr) { if(processed.indexOf(arr[obj].post_id) < 0) { processed.push(arr[obj].post_id); result.push(arr.filter(item => item.post_id == arr[obj].post_id).reduce((acc, currVal) => Object.assign(acc, currVal), {})); } } console.log(result);

Answer 5

这是一个使用Map的选项，使用for...of循环迭代输入并使用Object.assign()合并具有相同post.id的对象。 结果是将Map的.values()迭代器转换为数组。

 const input = [{ like_id: 1, likes: 1, post_id: 1, type: "feed_post_likes", _id: "b51771798ed01795cb8a17b028000329" }, { post_id: 1, created_date: "2021-03-10T10:54:35.264Z", post_message: "Happy", post_pic: "", post_type: "post" }]; const grouped = new Map(input.map(like => [like.post_id, {}])); for (let like of input) { Object.assign(grouped.get(like.post_id), like); } const result = [...grouped.values()]; console.log(result)