Question

我有一个对象，它有几个我想要提取的值，并放入另一个具有不同键的对象中。现在我正在使用解构来提取值，然后使用提取的值及其新键定义对象文字。

这是我的功能：

getProductReviewData() {
    const {
        averageRateDisplay,
        rawAverageRate,
        displayReviewCount,
        productReviewIds,
        productReviews
    } = this.productReviewsStore.getAll(); // this is deconstruction of an object
    return {
        ratingDisplay: averageRateDisplay,
        rating: rawAverageRate,
        ratingCount: displayReviewCount,
        reviewIds: productReviewIds,
        reviewMap: productReviews
    };
}

然而，我想知道这是否是一种速记方式，所以在解构和声明中使用一行。有谁知道这是否可行？

Answer 1

I don't think there's anything to put them in the same statement，特别是重命名。您当然可以编写自己的辅助函数来重命名对象属性。

我认为将对象分配给一个变量然后重复多次会比重复每个属性/变量名两次要清晰得多：

getProductReviewData() {
    const all = this.productReviewsStore.getAll();
    return {
        ratingDisplay: all.averageRateDisplay,
        rating:        all.rawAverageRate,
        ratingCount:   all.displayReviewCount,
        reviewIds:     all.productReviewIds,
        reviewMap:     all.productReviews
    };
}

如果您更好地¹，您还可以使用解构到对象属性来交换双方：

getProductReviewData() {
    let res = {};
    ({
        averageRateDisplay: res.ratingDisplay,
        rawAverageRate:     res.rating,
        displayReviewCount: res.ratingCount,
        productReviewIds:   res.reviewIds,
        productReviews:     res.reviewMap
    } = this.productReviewsStore.getAll());
    return res;
}

_{1：就我个人而言，我认为这只是一种不必要的混淆 - 而且还会延长一行！}

Answer 2

UPD：简单比复杂更好！我喜欢Bergi's answer =）

可能你可以声明新的密钥，然后在迭代中改变它们¯_（ツ）_ /¯

getProductReviewData() {
    //declare new keys
    const newKeys = {
        averageRateDisplay: "ratingDisplay",
        rawAverageRate:     "rating",
        displayReviewCount: "ratingCount",
        productReviewIds:   "reviewIds",
        productReviews:     "reviewMap"
    }
    const productReviewsStore = this.productReviewsStore.getAll();

    //return the object with replaced keys
    return Object.assign({},
      ...Object.keys(productReviewsStore)
           .filter(key => newKeys[key])
           .map(key => ({[newKeys[key]]: productReviewsStore[key]}))
    )
}

Answer 3

您可以一次性构造并提供新的键/变量值。但据我所知，你不能直接解构成一个新的对象。

const start = {
  averageRateDisplay: 1,
  rawAverageRate: 2,
  displayReviewCount: 3,
  productReviewIds: 4,
  productReviews: 5
 };

 // destructuring with renaming of variables
 const {
   // name to match : newName
   averageRateDisplay: ratingDisplay,
   rawAverageRate: rating,
   displayReviewCount: ratingCount,
   productReviewIds: reviewIds,
   productReviews: reviewMap
} = start;

// creating new object, using property value shorthand
// https://ariya.io/2013/02/es6-and-object-literal-property-value-shorthand
const end = {
    ratingDisplay,
  rating,
  ratingCount,
  reviewIds,
  reviewMap
};

console.log(end)

对象解构为对象声明？

3 个答案: