CODEWITHSUNDEEP
javascript
TheParrot12345
TheParrot12345

Reputation: 65

Calculate sum of array one array attribute and constructing by key

I have an object

let returnObj = {
   test_on_Home_Page: {
     page: 'Home Page',
     total_sum: -141.16874354518953,
     top_url: null
   },
  test_on_Product_List: {
     page: 'Product List',
     total_sum: -147.16874354518953,
     top_url: null
   },
  testOther_on_Home_page: {
     page: 'Home Page',
     total_sum: -48.16874354518953,
     top_url: null
   },
}

I want to calculate total_sum of Object keys by pages, like this

 {
    HomePage : -189.33744
    ProductList : -147.168743
  }

I have tried

let totalCart = 0;

for(let errorName of Object.keys(returnObj)){
    if(returnObj[errorName]['page'] == "Cart"){
    totalCart += returnObj[errorName]['total_sum'] 
    }
 }

But that doesn't look dynamic to me.

Can this be done with one line With something like this

 let list = [];
 
 for(let errorName of Object.keys(returnObj)){
    list[returnObj[errorName]] += returnObj[errorName]['total_sum']
    
    }

Upvotes: 0

Views: 49

Answers (3)

connexo
connexo

Reputation: 56754

Here's an approach using Array.prototype.reduce on Object.values(returnObj):

const o = {
  test_on_Home_Page: {
    page: 'Home Page',
    total_sum: -141.16874354518953,
    top_url: null
  },
  test_on_Product_List: {
    page: 'Product List',
    total_sum: -147.16874354518953,
    top_url: null
  },
  testOther_on_Home_page: {
    page: 'Home Page',
    total_sum: -48.16874354518953,
    top_url: null
  },
}

const sums = Object.values(o)
  .reduce((a, { page: p, total_sum: s }) => ({...a, ...{ [p]: (a[p] ?? 0) + s } }), {});

console.log(sums);

Upvotes: 0

user11816307
user11816307

Reputation:

If you want to use more of a functional aproach

const sums = {}
Object.values(returnObj).forEach(item => {
  sums[item.page] = (sums[item.page] ?? 0) + item.total_sum
})

Using the lodash lib:

const sums = {}
_.values(returnObj).forEach(item => {
  sums[item.page] = (sums[item.page] ?? 0) + item.total_sum
})

Upvotes: 0

gog
gog

Reputation: 11347

You need to iterate values, not keys:

let sums = {}

for (let obj of Object.values(returnObj))
    sums[obj.page] = (sums[obj.page] ?? 0) + obj.total_sum

Upvotes: 1

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