2.1: Operations

Learning Objectives

• Use mathematical operators to perform mathematical operations in the console of the browser

Introduction

Coding means writing instructions for the computer to execute. We will begin with the most basic instructions the computer can execute, which is operations between 2 number values.

Setup

1. Open a new tab in the Chrome browser by clicking File > New Tab, or pressing Cmd+T on Mac or Ctrl+T on Windows.

2. Open Chrome Developer Tools by clicking View > Developer > JavaScript Console, pressing Cmd+Option+I on Mac or Ctrl+Shift+I on Windows, or right-clicking anywhere in Chrome and clicking Inspect.

3. Select the Console tab in Chrome Dev Tools.

Accessing the Developer tools in the Chrome browser setting

You can use Ctrl + L or Cmd + K to clear your console

Exercises

The JavaScript language is capable of performing math operations. Enter the following calculations into the Chrome Dev Tools Console, followed by the Enter key.

Chrome console allows for in-browser calculations

2 + 2;

4 * 2;

4 / 2;

4 - 2;

The input here is a mathematical equation typed in by the user, you. You have instructed the computer to perform a mathematical operation. The computer _returned _ an output, the evaluation of the equation.

These exercises may seem trivial, but mathematical operations are at the core of all computing instructions. Computers fundamentally compute. That being said, they can get things predictably wrong. Try: 0.1 + 0.2 in your console. Did you get what you expect?

Coding Fundamentals will not cover why computers sometimes behave in odd ways, but you can read up more about this particular behaviour here and here.

Operators

In the above code, + * - and / are known as operators. Specifically, they are mathematical operators, as they perform a mathematical operation on 2 numbers. One other mathematical operator is the remainder operator, sometimes known as the modulus operator, defined with the % symbol. It returns the remainder after one number is divided by another; 10 % 3 will give us 1 because dividing 10 by 3 will result in a remainder of 1.

This course will only involve basic math: adding and subtracting (usually by 1), dividing and multiplying, and comparing numbers.

We will soon see other kinds of programming operators and operations; in the next section, we will see the assignment operator.