javascript - 比较 2 个数组 - 一个包含字符串，另一个包含数字。重复字符串的个数之和

Question

我有 2 个数组。让我们说

categories = ["hotels", "transfers","food","transfers"] 
amounts = [1500, 250, 165, 150]

我想生成一个输出对象的对象...

result = {hotels: 1500, transfers: 400, food: 165}

该函数应该循环遍历类别，填充结果对象，添加类别的唯一元素作为对象键，并将金额作为值。该函数还应该添加重复键的数量。

我已经尝试了几种方法，例如在数组上为每个嵌套 2 个，for 循环，...但我无法弄清楚任何有效的方法...

Answer 1

如果两个数组的索引始终保持同步，则可以这样做:

const categories = ["hotels", "transfers","food","transfers"];
const amounts = [1500, 250, 165, 150];
const result = {};

categories.forEach((category, index) => {
  const doesKeyExist = !!result[category];
  const amount = amounts[index];
  const correctAmount = doesKeyExist ? result[category] + amount : amount;

  result[category] = correctAmount;
}

这将产生您所期望的结果:

result = {hotels: 1500, transfers: 400, food: 165}