javascript - 对值求和，并将具有相同 id 的对象值合并到一个新数组中

Question

我有一个从服务器收到的项目对象。每个商品及其数量都必须由卖家保存，但是，在屏幕上显示时，我需要在新数组中独立于卖家对值进行总计。

[
    { code: 1, item: 'ball', salesman: 'Braan', quantity: 5, price: 10.00},
    { code: 1, item: 'shoe', salesman: 'Alex', quantity: 5, price: 20.00},
    { code: 1, item: 'ball', salesman: 'Max', quantity: 3, price: 10.00},
    { code: 1, item: 'shirt', salesman: 'Braan', quantity: 5, price: 15.00}
]

期望的输出是:

[
    { code: 1, item: 'ball', quantity: 8, price: 20.00},
    { code: 1, item: 'shoe', quantity: 5, price: 20.00},
    { code: 1, item: 'shirt', quantity: 5, price: 15.00}
]

Answer 1

基本上，您可以重新映射对象以删除 salesman 键。

const serverData = [{
    code: 1,
    item: 'ball',
    salesman: 'Braan',
    quantity: 5,
    price: 10.00
  },
  {
    code: 1,
    item: 'shoe',
    salesman: 'Alex',
    quantity: 5,
    price: 20.00
  },
  {
    code: 1,
    item: 'ball',
    salesman: 'Max',
    quantity: 3,
    price: 10.00
  },
  {
    code: 1,
    item: 'shirt',
    salesman: 'Braan',
    quantity: 5,
    price: 15.00
  }
]

const result = serverData
  .map((item, i, array) => {
    const defaultValue = {
      code: item.code,
      item: item.item,
      quantity: 0,
      price: 0
    }
    const finalValue = array
      .filter(other => other.item === item.item) //we filter the same items
      .reduce((accum, currentVal) => { //we reduce them into a single entry
        accum.quantity += currentVal.quantity;
        accum.price += currentVal.price;
        return accum;
      }, defaultValue);

    return finalValue;
  })
  .filter((item, thisIndex, array) => { //now our new array has duplicates, lets remove them
    const index = array.findIndex((otherItem, otherIndex) => otherItem.item === item.item && otherIndex !== thisIndex && otherIndex > thisIndex);

    return index === -1
  })

console.log(result)