# How To Find The Sum Of An Array Of Numbers in JavaScript – Definitive Guide

The Array objects help store a collection of multiple items under a single variable name and provide various functions for manipulating the array values.

You can use the `array.reduce()` method to find the sum of an array of numbers in JavaScript

## Using reduce (Quick Solution)

To find the sum of an array of numbers in JavaScript:

• You can use the `array.reduce()` method, which iterates through each array element and adds the current value to the previous value.
• Set the initial value of `reduce` to `0`, so the previous value will start with `0`.

Code

``````    const prices = [100, 200, 300, 400];
const totalPriceAmount = prices.reduce((previous, current) => previous + current, 0);
console.log(totalPriceAmount);``````

Output

``    1000``

The `reduce()` method iterates through the element and adds the `current value` to the `previous value`. Initially, the previous value will be assigned with `0`; later, it gets updated after each addition and returns the total sum.

## Using ForEach

You can also use simple ForEach to find the sum of an array of numbers

• Set a variable to hold the total sum(`let totalPriceAmount = 0`).
• Iterate the array using the `forEach` method.
• Add the current value to the total sum variable and retains the new value.

Code

``````    const prices = [100, 200, 300, 400];
let totalPriceAmount = 0;
prices.forEach(price => {
totalPriceAmount += price
})
console.log(totalPriceAmount);``````

Output

``    1000``

The array is iterated using `forEach`and the current element is added to the `totalPriceAmount` variable.

## ES6 for…of

The `for...of` statement creates a loop iterating over like string, array.
To hold the total sum, you can add the current iterated value to a variable.
Code

``````    const prices = [100, 200, 300, 400];
let totalPriceAmount = 0;
for (let value of prices) {
totalPriceAmount += value;
}
console.log(totalPriceAmount);``````

Output

``    1000``

## Using For Loop

You can also use a simple for loop to iterate through a simple for loop and get the current value added to a variable.
Code

``````    const prices = [100, 200, 300, 400];
let totalPriceAmount = 0;
for (var i = 0; i < prices.length; i++) {
totalPriceAmount += prices[i];
}
console.log(totalPriceAmount);``````

Output

``    1000``

## Using While Loop

A while loop execution will also help to iterate through an array, add the current value to a variable, and get the total sum of an array.
Code

``````    const prices = [100, 200, 300, 400];
let totalPriceAmount = 0,
i = -1;
while (++i < prices.length) {
totalPriceAmount += prices[i];
}
console.log(totalPriceAmount);``````

Output

``    1000``