Javascript-汇总对象数组中已出现产品的数量

Question

我有以下这样的数组

[
 {name: "calpol", quantity: 12},
 {name: "paracetamol", quantity: 15},
 {name: "paracetamol", quantity: 10},
]

当产品相同时，我想总结数量，这样我就可以获得像这样的数组：

[
 {name: "calpol", quantity: 12},
 {name: "paracetamol", quantity: 25},
]

Answer 1

使用reduce并在累加器数组中检查是否存在名称如calpol或扑热息痛的对象。如果存在，则更新数量，否则创建新对象并将其推入累加器

let prod = [{
    name: "calpol",
    quantity: 12
  },
  {
    name: "paracetamol",
    quantity: 15
  },
  {
    name: "paracetamol",
    quantity: 10
  },
]

let sum = prod.reduce(function(acc, curr) {
  let findIndex = acc.findIndex(item => item.name === curr.name);

  if (findIndex === -1) {
    acc.push(curr)
  } else {

    acc[findIndex].quantity += curr.quantity
  }
  return acc;
}, [])

console.log(sum)