w3schools javascript rectangle area code example

Example 1: how to make a rectangle in javascript

const canvas = document.getElementById('pong') // first make a index . html with a canvas height and width and id of pong or whatever
// and then we have to get access to our context to draw on it
const context = canvas.getContext('2d')

// then you do...

context.drawRect(20, 20, 150, 150);
context.fillStyle = '#fff' // thats white!!

Example 2: draw rectangle on canvas javascript

//Assuming you have canvas and context (ctx) set up:
ctx.fillStyle = "(enter color)";
ctx.fillRect(x, y, width, height);
//to set up canvas and context:
var canvas = document.getElementById("(enter canvas's id)");
var ctx = canvas.getContext("2d");