const canvas = document.createElement('canvas'); canvas.width = 600; canvas.height = 400; document.body.appendChild(canvas); const ctx = canvas.getContext('2d');

let circle = { x: 50, y: 200, radius: 20, dx: 2 };

function drawCircle() { ctx.clearRect(0, 0, canvas.width, canvas.height); ctx.beginPath(); ctx.arc(circle.x, circle.y, circle.radius, 0, Math.PI * 2); ctx.fillStyle = 'red'; ctx.fill(); ctx.closePath();

circle.x += circle.dx; if (circle.x + circle.radius > canvas.width || circle.x - circle.radius < 0) { circle.dx *= -1; } }

function animate() { drawCircle(); requestAnimationFrame(animate); }

animate();