Performing array reduction and summation on objects in JavaScript

Question

Performing array reduction and summation on objects in JavaScript

Data Analysis:

dataSet: [],
models: [
    { id: 1, name: "samsung", seller_id: 1, count: 56 },
    { id: 1, name: "samsung", seller_id: 2, count: 68 },
    { id: 2, name: "nokia", seller_id: 2, count: 45 },
    { id: 2, name: "nokia", seller_id: 3, count: 49 }
]

Desired Output:

dataSet: [
    { id: 1, name: "samsung", count: 124 },
    { id: 2, name: "nokia", count: 94 }
]

This script aims to simplify the data set by removing duplicate ids:

this.models.forEach(mdl => {
    if (!this.dataSet.some(obj => obj.id === mdl.id)) {
        this.dataSet.push(mdl);
    }
});

However, the challenge lies in summing up the count values.
Any suggestions on how to achieve this?

javascript arrays json vue.js

Answer 1

Answer №1

You have the option to utilize Array.reduce():

var mobiles = [
    { id: 1, name: "samsung", seller_id: 1, count: 56 },
    { id: 1, name: "samsung", seller_id: 2, count: 68 },
    { id: 2, name: "nokia", seller_id: 2, count: 45 },
    { id: 2, name: "nokia", seller_id: 3, count: 49 }
];

var phones = mobiles.reduce((acc, item) => {
  let existingItem = acc.find(({id}) => item.id === id);
  if(existingItem) {
    existingItem.count += item.count;
  } else {
    acc.push(item);
  }
  return acc;
}, []);

console.log(phones);

Therefore, in your code, you can replace variables with this.arr and this.mobiles, updating them accordingly:

this.arr = this.mobiles.reduce((acc, item) => {
  let existingItem = acc.find(({id}) => item.id === id);
  if(existingItem) {
    existingItem.count += item.count;
  } else {
    acc.push(item);
  }
  return acc;
}, []);

Answer 2

You have the option to utilize Array.reduce():

var mobiles = [
    { id: 1, name: "samsung", seller_id: 1, count: 56 },
    { id: 1, name: "samsung", seller_id: 2, count: 68 },
    { id: 2, name: "nokia", seller_id: 2, count: 45 },
    { id: 2, name: "nokia", seller_id: 3, count: 49 }
];

var phones = mobiles.reduce((acc, item) => {
  let existingItem = acc.find(({id}) => item.id === id);
  if(existingItem) {
    existingItem.count += item.count;
  } else {
    acc.push(item);
  }
  return acc;
}, []);

console.log(phones);

Therefore, in your code, you can replace variables with this.arr and this.mobiles, updating them accordingly:

this.arr = this.mobiles.reduce((acc, item) => {
  let existingItem = acc.find(({id}) => item.id === id);
  if(existingItem) {
    existingItem.count += item.count;
  } else {
    acc.push(item);
  }
  return acc;
}, []);

Answer 3

Answer №2

To replace the usage of some, you can opt for Object.values. In the reduce function, construct an object with the key as id and values from the models. Afterwards, employ Object.values to generate an array consisting of these values.

let models = [{
    id: 1,
    name: "samsung",
    seller_id: 1,
    count: 56
  },
  {
    id: 1,
    name: "samsung",
    seller_id: 2,
    count: 68
  },
  {
    id: 2,
    name: "nokia",
    seller_id: 2,
    count: 45
  },
  {
    id: 2,
    name: "nokia",
    seller_id: 3,
    count: 49
  }
]
let data = models.reduce((acc, curr) => {
  if (!acc[curr.id]) {
    acc[curr.id] = curr;
  } else {
    acc[curr.id].count += curr.count

  }
  return acc;
}, {})
console.log(Object.values(data))

Answer 4

To replace the usage of some, you can opt for Object.values. In the reduce function, construct an object with the key as id and values from the models. Afterwards, employ Object.values to generate an array consisting of these values.

let models = [{
    id: 1,
    name: "samsung",
    seller_id: 1,
    count: 56
  },
  {
    id: 1,
    name: "samsung",
    seller_id: 2,
    count: 68
  },
  {
    id: 2,
    name: "nokia",
    seller_id: 2,
    count: 45
  },
  {
    id: 2,
    name: "nokia",
    seller_id: 3,
    count: 49
  }
]
let data = models.reduce((acc, curr) => {
  if (!acc[curr.id]) {
    acc[curr.id] = curr;
  } else {
    acc[curr.id].count += curr.count

  }
  return acc;
}, {})
console.log(Object.values(data))

Performing array reduction and summation on objects in JavaScript

Answer №1

Answer №2

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