Teaching / Intro to Creative Web Dev / Creating Variables - Week 03

Creating Variables - Week 03

Welcome to week 3 of Intro to Creative Web Dev!

Now you know how to use p5.js to write code and call functions to draw on the screen, and you know how to use variables like width and height.

This week, you’ll learn how to create your own variables and make p5.js do math for you.

Work through the activities in this page to complete the week!

Creating Variables

First, read through this tutorial:


Now you know how to create your own variables and how to make p5.js do math for you. You’ve also seen a little bit of randomness!

To practice that, create a p5.js sketch that creates your own variables.

If it helps, here are a couple code-alongs for how I would approach the project:

This code-along creates a sketch from an abstract shape:

This code-along creates a sketch from randomly generated cats:

Your sketch must run without any errors. Your sketch must contain at least ten variables that you create using the let keyword and then use either as function parameters or to calculate the value of another variable.

For example:

function setup() {
  createCanvas(400, 400);

function draw() {

  let pointOneX = random(width);
  let pointOneY = random(height);
  let pointTwoX = random(width);
  let pointTwoY = random(height);
  let midPointX = (pointOneX + pointTwoX) / 2;
  let midPointY = (pointOneY + pointTwoY) / 2;

  line(pointOneX, pointOneY, pointTwoX, pointTwoY);
  circle(midPointX, midPointY, 25);

This code creates 6 variables that it uses to draw a circle on the midpoint of a random line. Using randomness is optional! The important piece is that you’re practicing using variables by creating and using 10 variables.