Combining property values based on a common property in an array of objects using JavaScript

Question

Combining property values based on a common property in an array of objects using JavaScript

I have a large array filled with various objects structured like:

[
        {
          "type": "bananas",
          "count": 15
        },
        {
          "type": "kiwis",
          "count": 20
        },
        {
          "type": "bananas",
          "count": 5
        },
        {
          "type": "strawberries",
          "count": 10
        },
        {
          "type": "strawberries",
          "count": 25
        }
]

My goal is to iterate through the array and combine counts for objects with matching types. Using the provided example, the desired output would be:

[
        {
          "type": "bananas",
          "count": 20
        },
        {
          "type": "kiwis",
          "count": 20
        },
        {
          "type": "strawberries",
          "count": 35
        },
]

If anyone has any tips or guidance on how to achieve this, I would really appreciate it.

javascript arrays angular typescript

Answer 1

Answer №1

One approach could be to utilize the reduce method, taking advantage of ES6 syntax.

let items = [
        {
          "type": "bananas",
          "quantity": 15
        },
        {
          "type": "grapes",
          "quantity": 25
        },
        {
          "type": "bananas",
          "quantity": 10
        },
        {
          "type": "apples",
          "quantity": 30
        },
        {
          "type": "apples",
          "quantity": 20
        }
]

let combinedItems = items.reduce((accumulator, currentValue) => {
  let existingItem = accumulator.find(item => item.type === currentValue.type);
  if (existingItem) {
    existingItem.quantity += currentValue.quantity;
  } else {
    accumulator.push(currentValue);
  }
  return accumulator;
},[])

console.log(combinedItems)

Answer 2

One approach could be to utilize the reduce method, taking advantage of ES6 syntax.

let items = [
        {
          "type": "bananas",
          "quantity": 15
        },
        {
          "type": "grapes",
          "quantity": 25
        },
        {
          "type": "bananas",
          "quantity": 10
        },
        {
          "type": "apples",
          "quantity": 30
        },
        {
          "type": "apples",
          "quantity": 20
        }
]

let combinedItems = items.reduce((accumulator, currentValue) => {
  let existingItem = accumulator.find(item => item.type === currentValue.type);
  if (existingItem) {
    existingItem.quantity += currentValue.quantity;
  } else {
    accumulator.push(currentValue);
  }
  return accumulator;
},[])

console.log(combinedItems)

Answer 3

Answer №2

How about this code snippet to sum up counts for different types of fruits:

const fruitData = [
  {
    name: 'apples',
    quantity: 10
  },
  {
    name: 'oranges',
    quantity: 20
  },
  {
    name: 'apples',
    quantity: 5
  },
  {
    name: 'grapes',
    quantity: 20
  },
  {
    name: 'grapes',
    quantity: 10
  }
];

const fruitTypes = fruitData.map((fruit) => fruit.name);
const uniqueFruitTypes = [...new Set(fruitTypes)];

const totalQuantities = uniqueFruitTypes.map((fruitType) => ({
  name: fruitType,
  quantity: fruitData
    .filter((fruit) => fruit.name === fruitType)
    .map((fruit) => fruit.quantity)
    .reduce((acc, currQuantity) => acc + currQuantity, 0)
}));

Answer 4

How about this code snippet to sum up counts for different types of fruits:

const fruitData = [
  {
    name: 'apples',
    quantity: 10
  },
  {
    name: 'oranges',
    quantity: 20
  },
  {
    name: 'apples',
    quantity: 5
  },
  {
    name: 'grapes',
    quantity: 20
  },
  {
    name: 'grapes',
    quantity: 10
  }
];

const fruitTypes = fruitData.map((fruit) => fruit.name);
const uniqueFruitTypes = [...new Set(fruitTypes)];

const totalQuantities = uniqueFruitTypes.map((fruitType) => ({
  name: fruitType,
  quantity: fruitData
    .filter((fruit) => fruit.name === fruitType)
    .map((fruit) => fruit.quantity)
    .reduce((acc, currQuantity) => acc + currQuantity, 0)
}));

Combining property values based on a common property in an array of objects using JavaScript

Answer №1

Answer №2

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