Iterating through an array of objects and performing reduction based on various key-value pairs

Question

Iterating through an array of objects and performing reduction based on various key-value pairs

I am faced with a challenge of consolidating a large array of objects into one single array that has a specific structure. Each item, such as a banana, needs to be present in two separate objects for buy orders and sell orders, each with their own distinct price and data.

I attempted to identify the unique pairings of items (banana, apple, orange, etc.) and loop through them, while also nesting another map function for the data processing, but I have not been able to find a solution yet.

let uniquePairing = Array.from([...new Set(data.map(item => item["name"]))])


**let data = [{
name:'banana,
price:( average cost)
type:buy
items: ( total bananas)
fee: ( total fees)
},
{
name:'banana,
price:( average cost)
type:sell
items: ( total bananas)
fee: ( total fees)
},
{ apples...
]**

Example of data

let data = [
{
name:"banana",
price:1,
type: "buy",
fee: 0.5,
items:25
},
{
name:"banana",
price:1.2,
type: "buy",
fee: 0.5,
items:25
},
{
name:"banana",
price:2,
type: "sell",
fee: 0.5,
items:25
},
{
name:"apple",
price:1,
type: "buy"
fee: 0.5
items:25
},
{
name:"apple",
price:1.2,
type: "buy",
fee: 0.5,
items:25
},
{
name:"apple",
price:2,
type: "sell",
fee: 0.5,
items:25
}
]

javascript

Answer 1

Answer №1

It seems like you're looking for a solution using the reduce function:

const uniqueItems = data.reduce((accumulator, currentItem) => {
  const name = currentItem.name,
        type = currentItem.type;

  let matchedItem = accumulator.find(item => item.name === name && item.type === type);
  
  if (!matchedItem) {
    accumulator.push({
      ...currentItem,
      totalPrice: currentItem.price,
      objCount: 1
    });
  } else {
    matchedItem.totalPrice += currentItem.price;
    matchedItem.objCount++;
    matchedItem.price = matchedItem.totalPrice / matchedItem.objCount;
    matchedItem.items += currentItem.items;
    matchedItem.fee += currentItem.fee;
  }

  return accumulator;
}, []);

Answer 2

It seems like you're looking for a solution using the reduce function:

const uniqueItems = data.reduce((accumulator, currentItem) => {
  const name = currentItem.name,
        type = currentItem.type;

  let matchedItem = accumulator.find(item => item.name === name && item.type === type);
  
  if (!matchedItem) {
    accumulator.push({
      ...currentItem,
      totalPrice: currentItem.price,
      objCount: 1
    });
  } else {
    matchedItem.totalPrice += currentItem.price;
    matchedItem.objCount++;
    matchedItem.price = matchedItem.totalPrice / matchedItem.objCount;
    matchedItem.items += currentItem.items;
    matchedItem.fee += currentItem.fee;
  }

  return accumulator;
}, []);

Answer 3

Answer №2

One way to achieve this is by following the steps below:

   let collection = [
{
name:"banana",
price:1,
type: "buy",
fee: 0.5,
items:25
},
{
name:"banana",
price:1.2,
type: "buy",
fee: 0.5,
items:25
},
{
name:"banana",
price:2,
type: "sell",
fee: 0.5,
items:25
},
{
name:"apple",
price:1,
type: "buy",
fee: 0.5,
items:25
},
{
name:"apple",
price:1.2,
type: "buy",
fee: 0.5,
items:25
},
{
name:"apple",
price:2,
type: "sell",
fee: 0.5,
items:25
}
]

const getFruitDetails = (fruits, fruit) => fruits.filter(fr=> fr.name===fruit.name && fr.type=== fruit.type)

const calculateTotal = (fruits, field) => fruits.reduce((acc,cur)=> acc+=cur[field], 0)

const checkIfRegistered = (fruits, value) => fruits.some(fruit=> fruit.type === value.type && fruit.name===value.name)

const extractFruits = (fruits) => {
  return fruits.reduce((acc, cur)=> {
if(checkIfRegistered(acc, cur)){
  return acc
}
acc.push({name: cur.name, type: cur.type})
return acc
  }, [])
}

function mergeCollection(arr){
  const fruits = extractFruits(arr)
  return fruits.map(fruit=> {
const data = getFruitDetails(arr, fruit)
return {
  name: fruit.name,
  price: calculateTotal(data, "price"),
  type: fruit.type,
  fee: calculateTotal(data, "fee"),
  items: calculateTotal(data, "items")
}
  })
}

console.log(mergeCollection(collection))

Answer 4

One way to achieve this is by following the steps below:

   let collection = [
{
name:"banana",
price:1,
type: "buy",
fee: 0.5,
items:25
},
{
name:"banana",
price:1.2,
type: "buy",
fee: 0.5,
items:25
},
{
name:"banana",
price:2,
type: "sell",
fee: 0.5,
items:25
},
{
name:"apple",
price:1,
type: "buy",
fee: 0.5,
items:25
},
{
name:"apple",
price:1.2,
type: "buy",
fee: 0.5,
items:25
},
{
name:"apple",
price:2,
type: "sell",
fee: 0.5,
items:25
}
]

const getFruitDetails = (fruits, fruit) => fruits.filter(fr=> fr.name===fruit.name && fr.type=== fruit.type)

const calculateTotal = (fruits, field) => fruits.reduce((acc,cur)=> acc+=cur[field], 0)

const checkIfRegistered = (fruits, value) => fruits.some(fruit=> fruit.type === value.type && fruit.name===value.name)

const extractFruits = (fruits) => {
  return fruits.reduce((acc, cur)=> {
if(checkIfRegistered(acc, cur)){
  return acc
}
acc.push({name: cur.name, type: cur.type})
return acc
  }, [])
}

function mergeCollection(arr){
  const fruits = extractFruits(arr)
  return fruits.map(fruit=> {
const data = getFruitDetails(arr, fruit)
return {
  name: fruit.name,
  price: calculateTotal(data, "price"),
  type: fruit.type,
  fee: calculateTotal(data, "fee"),
  items: calculateTotal(data, "items")
}
  })
}

console.log(mergeCollection(collection))

Iterating through an array of objects and performing reduction based on various key-value pairs

Answer №1

Answer №2

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