javascript - 如何在两个不同的数组上获得总长度或计数

Question

我知道这个问题很难理解，所以我会解释我希望它如何我有这个数据数组:

const products = [
  {
    name: "Product A",
    reviews: [
      {
        comment: "Good Product",
        username: "Alif",
      },
    ],
  },
  {
    name: "Product B",
    reviews: [
      {
        comment: "Bad Product",
        username: "Alif",
      },
      {
        comment: "Good Product",
        username: "Atif",
      },
      {
        comment: "Ok Product",
        username: "Esha",
      },
    ],
  },
];


products.map(({ reviews }) => {
  console.log(reviews.length);
});

我想获得评论的长度，但由于两个对象是分开的，即产品 A 和产品 B，我得到分开的长度或像这样计数:

我希望结果是总长度为 4 或计数为 4，所以我想到了合并数组。还有其他方法吗？

Answer 1

一个天真的解决方案可能是:

const products = [{
    name: "Product A",
    reviews: [{
      comment: "Good Product",
      username: "Alif",
    }, ],
  },
  {
    name: "Product B",
    reviews: [{
        comment: "Bad Product",
        username: "Alif",
      },
      {
        comment: "Good Product",
        username: "Atif",
      },
      {
        comment: "Ok Product",
        username: "Esha",
      },
    ],
  },
];

const allProducts = products.flatMap(({
  reviews
}) => reviews);

console.log(allProducts.length);

这会映射每个产品并提取评论数组，然后将其扁平化为一个数组。