Array Reduction in JavaScript

Introduction

In this lab, we will be exploring the use of the Array.prototype.reduce() method to calculate the sum of two or more numbers/arrays. We will learn how to initialize an accumulator with a value of 0 and how to use the spread operator to pass an array as individual arguments. By the end of this lab, you will have a better understanding of how to use the reduce() method in JavaScript.

Here's how to find the sum of an array

To find the sum of an array of numbers, follow these steps:

1. Open the Terminal/SSH and type node to start coding.
2. Use the Array.prototype.reduce() method to add each value to an accumulator, which should be initialized with a value of 0.
3. Here's the code you can use to find the sum of the array:

const sum = (...arr) => [...arr].reduce((acc, val) => acc + val, 0);

4. To test the sum function, use the following code examples:

sum(1, 2, 3, 4); // 10
sum(...[1, 2, 3, 4]); // 10

By following these steps, you can easily find the sum of an array of numbers using JavaScript.

Summary

Congratulations! You have completed the Array Sum lab. You can practice more labs in LabEx to improve your skills.