# How to find the sum of numbers in an array javascript

**by Sai gowtham1min read**

In this tutorial we are going to learn two ways to find the sum of an array of numbers by using JavaScript.

### First way using for of loop.

```
let arr = [1,2,3,4,5];
let sum = 0;
for (let num of arr){
sum = sum + num
}
console.log(sum) // 15
```

In the above code, we used `for of loop`

to get the `number`

directly instead of `index`

.

On each iteration, we have added the `number`

to `sum`

variable.

### Array.reduce( ) method

There is an inbuilt `reduce`

method in JavaScript which helps to calculate the sum of numbers in the array.

```
let arr = [1,2,3,4,5];
const sum = arr.reduce((result,number)=> result+number);
console.log(sum) // 15
```

In the above code on each iteration reducer function store, the numbers sum inside the `result`

parameter and finally returns the result value.

`reduce()`

method takes the callback function as its first argument and runs that callback function on each element present in the array.

The callback function takes two parameters `result`

and `current`

element.