How to draw a circle in HTML5 Canvas using JavaScript?

Question

How to draw a simple circle in HTML5 Canvas using minimum JavaScript code?

Answer 1

Creating shapes is easier using new Canvas Path2D, which uses the same canvas drawing API, and allow separation of the declaration from drawing itself, and reuse of complex geometry:

var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
var centerX = canvas.width / 2;
var centerY = canvas.height / 2;
var radius = 70;

let circle = new Path2D();  // <<< Declaration
circle.arc(centerX, centerY, radius, 0, 2 * Math.PI, false);

context.fillStyle = 'blue';
context.fill(circle); //   <<< pass circle to context

context.lineWidth = 10;
context.strokeStyle = '#000066';
context.stroke(circle);  // <<< pass circle here too

body {
margin: 0px;
padding: 0px;
}