How can I sum data of my first array with data of array in it?
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?
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());
const total = obj.accounts.reduce((a, { balance, payments }) => ( a + payments.reduce((accum, { balance }) => accum + balance, balance) ), 0); how can I use this part in my code? PS: I'm using vue.js and my code is placed in methods: {...}
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;
},
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);
1 what is the difference between your way and Jaydip Rakholiya way? i mean which one has better functionality? 2 and if i want to use your way what would be the code exactly? (based on my function)
ES6 syntax and reduce method.When you want to get a single value after performing a same operation over each array of objects then reduce is more relevant and meant for itI 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');
this.accountsis not null.