how to make a javascript game
//Javascript game template
//Move player with arrow keys
var canvas = document.createElement("canvas");
canvas.width = 500;
canvas.height = 500;
document.body.appendChild(canvas);
var ctx = canvas.getContext("2d");
var player = {x: canvas.width / 2, y: canvas.height / 2, speed: 10};
var keys = [];
function update() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.beginPath();
ctx.fillStyle = "red";
ctx.fillRect(player.x, player.y, 50, 50);
if (keys[37])
player.x -= player.speed;
if (keys[38])
player.y -= player.speed;
if (keys[39])
player.x += player.speed;
if (keys[40])
player.y += player.speed;
requestAnimationFrame(update);
}
update();
document.onkeydown = function(e) {
keys[e.keyCode] = true;
}
document.onkeyup = function(e) {
keys[e.keyCode] = false;
}