I have the following array :

[
 { name: "iPhone 12", quantity: 12, price: 325, … },
 { name: "iPhone 12", quantity: 4, price: 325, … },
 { name: "iPhone 13", quantity: 2, price: 525, … },
 { name: "iPhone 12", quantity: 2, price: 325 },
 { name: "iPhone 13", quantity: 3, price: 525 },
 { name: "iPhone SE", quantity: 2, price: 59 }
]

And I want to sum the quantity properties of each object in order to have an array with distinct elements like this :

[
  { name: "iPhone 12", quantity: 18, price: 325 },
  { name: "iPhone 13", quantity: 5, price: 525 },
  { name: "iPhone SE", quantity: 2, price: 59 }
]

How can I do that?

CodePudding user response：

Seems like a good task for Array.prototype.reduce

const data = [{
    name: "iPhone 12",
    quantity: 12,
    price: 325,
  },

  {
    name: "iPhone 12",
    quantity: 4,
    price: 325,
  },

  {
    name: "iPhone 13",
    quantity: 2,
    price: 525,

  },

  {
    name: "iPhone 12",
    quantity: 2,
    price: 325
  },

  {
    name: "iPhone 13",
    quantity: 3,
    price: 525
  },
]
const summed = data.reduce((sum, current) => {
  const item = sum.find(el => el.name === current.name)
  if (item) {
    for (const key in item) {
      if (key === 'name') continue
      item[key]  = current[key]
    }
  } else {
    sum.push({ ...current })
  }
  return sum
}, [])

console.log(summed)