## Issue

I am trying to solve "A very big sum" challenge on Hacker Rank: https://www.hackerrank.com/challenges/a-very-big-sum/problem

In there I have to sum all the numbers in the array given so I came up with two solutions:

**First solution**

```
function aVeryBigSum(ar){
let sum = 0;
for(let i = 0; i < ar.length; i++){
sum += i;
}
}
```

**Second Solution**

```
function(ar){
let sum = ar.reduce((accumulator, currentValue) => {
accumulator + currentValue;
});
}
```

But none of them work and I donĀ“t know why, I am thiniking maybe I am not writing it as Hacker Rank wants me to but I am not sure

## Solution

`sum += i;`

should be `sum += ar[i];`

Also return sum

```
function aVeryBigSum(ar){
let sum = 0;
for(let i = 0; i < ar.length; i++){
sum += ar[i];
}
return sum;
}
```

Also reducer function should be like

```
function a(ar){
let sum = (accumulator, currentValue) => accumulator + currentValue;
return ar.reduce(sum);
}
```

Answered By – Kenny

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