<!DOCTYPE html><html><head><title></title><style>
html, body {height:100%;margin:0;}
body {background: black;display: flex;align-items: center;justify-content: center;}
canvas {border:1px solid white;}</style></head><body><canvaswidth="400"height="400"id="game"></canvas><script>var canvas = document.getElementById('game');var context = canvas.getContext('2d');var grid =16;var count =0;var snake ={
x:160,
y:160,// snake velocity. moves one grid length every frame in either the x or y direction
dx: grid,
dy:0,// keep track of all grids the snake body occupies
cells:[],// length of the snake. grows when eating an apple
maxCells:4};var apple ={
x:320,
y:320};// get random whole numbers in a specific range// @see https://stackoverflow.com/a/1527820/2124254function getRandomInt(min, max){returnMath.floor(Math.random()*(max - min))+ min;}// game loopfunction loop(){
requestAnimationFrame(loop);// slow game loop to 15 fps instead of 60 (60/15 = 4)if(++count <4){return;}
count =0;
context.clearRect(0,0,canvas.width,canvas.height);// move snake by it's velocity
snake.x += snake.dx;
snake.y += snake.dy;// wrap snake position horizontally on edge of screenif(snake.x <0){
snake.x = canvas.width - grid;}elseif(snake.x >= canvas.width){
snake.x =0;}// wrap snake position vertically on edge of screenif(snake.y <0){
snake.y = canvas.height - grid;}elseif(snake.y >= canvas.height){
snake.y =0;}// keep track of where snake has been. front of the array is always the head
snake.cells.unshift({x: snake.x, y: snake.y});// remove cells as we move away from themif(snake.cells.length > snake.maxCells){
snake.cells.pop();}// draw apple
context.fillStyle ='red';
context.fillRect(apple.x, apple.y, grid-1, grid-1);// draw snake one cell at a time
context.fillStyle ='green';
snake.cells.forEach(function(cell, index){// drawing 1 px smaller than the grid creates a grid effect in the snake body so you can see how long it is
context.fillRect(cell.x, cell.y, grid-1, grid-1);// snake ate appleif(cell.x === apple.x && cell.y === apple.y){
snake.maxCells++;// canvas is 400x400 which is 25x25 grids
apple.x = getRandomInt(0,25)* grid;
apple.y = getRandomInt(0,25)* grid;}// check collision with all cells after this one (modified bubble sort)for(var i = index +1; i < snake.cells.length; i++){// snake occupies same space as a body part. reset gameif(cell.x === snake.cells[i].x && cell.y === snake.cells[i].y){
snake.x =160;
snake.y =160;
snake.cells =[];
snake.maxCells =4;
snake.dx = grid;
snake.dy =0;
apple.x = getRandomInt(0,25)* grid;
apple.y = getRandomInt(0,25)* grid;}}});}// listen to keyboard events to move the snake
document.addEventListener('keydown',function(e){// prevent snake from backtracking on itself by checking that it's // not already moving on the same axis (pressing left while moving// left won't do anything, and pressing right while moving left// shouldn't let you collide with your own body)// left arrow keyif(e.which ===37&& snake.dx ===0){
snake.dx =-grid;
snake.dy =0;}// up arrow keyelseif(e.which ===38&& snake.dy ===0){
snake.dy =-grid;
snake.dx =0;}// right arrow keyelseif(e.which ===39&& snake.dx ===0){
snake.dx = grid;
snake.dy =0;}// down arrow keyelseif(e.which ===40&& snake.dy ===0){
snake.dy = grid;
snake.dx =0;}});// start the game
requestAnimationFrame(loop);</script></body></html>
Snake HTML Game:
Code: