Canvas is a special drawing field in the
JavaScript browser. This field is created
using the <canvas>
tag, which
should be given a width and height:
<canvas width="200" height="200"></canvas>
To work with this field in JavaScript, first we get a reference to this tag into some variable:
let canvas = document.querySelector('canvas');
Then the getContext
method
must be applied to this variable:
let canvas = document.querySelector('canvas');
let ctx = canvas.getContext('2d');
It can be simplified:
let ctx = document.querySelector('canvas').getContext('2d');
As a result, an object containing the
so-called drawing context will
be written to the ctx
variable.
All drawing will be done using the
methods of this object. We will study
them in the next lessons.