CODEWITHSUNDEEP
javascript
mafortis
mafortis

Reputation: 7138

How to sum two arrays data in JavaScript

How can I sum data of my first array with data of array in it?

one

code

this is my current code which is working on first array only

calculateTotal: function(){
  var sum=0;
  for(var i=0;i<this.accounts.length;i++){
     sum += this.accounts[i].balance;
  }
  return sum;
},

What should I change in this code to get the result i want?

Upvotes: 0

Views: 2593

Answers (4)

Bibek Shah
Bibek Shah

Reputation: 429

I just tried making a more generic type of solution to count a given key which can be nested into as many arrays or objects as you wish.

summarize = (obj, sum_key) => {
  var sum = 0;
  for ( key in obj ) {
    if (key == sum_key) {
      sum += obj[key];
    } else if (typeof obj[key] == 'object' && obj[key]) {
      sum += summarize(obj[key]);
    }
  }
  return sum;
};

Now you can get the required sum with:

summarize(data, 'balance');

Upvotes: 0

CodeZombie
CodeZombie

Reputation: 2087

Use reduce for this case 

  sumOfPaymentBalance = accounts.payments.reduce((sum,currentValue)=> 
                          (sum+currentValue.balance),0);
    mainBalance = accounts.reduce(sum,paymentValue=>(sum,paymentValue.balance),0);
    sumOfPaymentBalance += mainBalance;
    console.log(sumOfBalance);

Upvotes: 0

CertainPerformance
CertainPerformance

Reputation: 371193

You need not only the balance property, but you also need to add every balance property in the payments array. You can do this very concisely with reduce, passing in the outer balance as the initial value of the accumulator:

const obj = {
  accounts: [{
    balance: 150000,
    payments: [{
        balance: 100000,
      },
      {
        balance: -200000,
      }
    ]
  }]
};
const total = obj.accounts.reduce((a, { balance, payments }) => (
  a + payments.reduce((accum, { balance }) => accum + balance, balance)
), 0);
console.log(total);

Or, in object method form:

const obj = {
  calculateTotal() {
    return obj.accounts.reduce((a, { balance, payments }) => (
      a + payments.reduce((accum, { balance }) => accum + balance, balance)
    ), 0)
  },
  accounts: [{
    balance: 150000,
    payments: [{
        balance: 100000,
      },
      {
        balance: -200000,
      }
    ]
  }]
};
console.log(obj.calculateTotal());

Upvotes: 2

Jaydip Rakholiya
Jaydip Rakholiya

Reputation: 802

Can you try this? 

 calculateTotal: function(){
      var sum=0;
      for(var i=0;i<this.accounts.length;i++){
         sum += this.accounts[i].balance;
         // iterate over payments sub array in each account and add balance into the sum
         for(var j=0;j<this.accounts[i].payments.length;j++){
             sum += this.accounts[i].payments[j].balance;
         }
      }
      return sum;
    },

Upvotes: 1

Related Questions