Before You Begin

Open the IDE and the Terminal to implement this solution.

Aim

Learn how to write a basic Node.js file and run it.

Scenario

You are writing a very basic mathematical library with handy mathematical functions.

Steps for Completion

1. Create your project directory (folder), where all the code for this and other chapters will be kept. You can call it beginning-nodejs for brevity. Inside this directory, create another directory named lesson-1, and inside that, create another directory called activity-a. All this can be done using the following command:

mkdir -p beginning-nodejs/lesson-1/activity-a

2. Inside activity-a, create a file using touch maths.js command.  
3. Inside this file, create the following functions:
   • add: This takes any two numbers and returns the sum of both, for example, add(2, 5) returns 7
   • sum: Unlike add, takes any number of numbers and returns their sum, for example, sum(10, 5, 6) returns 21
4.  After these functions, write the following code to act as tests for your code:

console.log(add(10, 6)); // 16
console.log(sum(10, 5, 6)); // 21

5. Now, on the Terminal, change directory to lesson-1. That's where we will be running most of our code from for the whole chapter.
6. To run the code, run the following command:

node activity-a/math.js

The 16 and 21 values should be printed out on the Terminal.