Many people who are starting out with a new project get caught up in decidingon technologies, what frameworks to use and what database to pick. When often —especially if you are a beginner — it is a better idea to just get started,and make something with the tools you know.

This is the first part of a tutorial that will show how you can build a snake game in less thana hundred lines of JavaScript, without any frameworks. There is some HTMLand CSS in addition, but nothing scary. Any beginner to the web platform shouldbe able to go through the guide, and experienced developers will learnsomething new as well.

Getting started with Snake

Basic Snake HTML Game. Snake is a fun game to make as it doesn't require a lot of code (less than 100 lines with all comments removed). This is a basic implementation of the snake game, but it's missing a few things intentionally and they're left as further exploration for the reader. Here we are going to make a simple 8-bit Snake Game. The important point is that our snake is formed by a chain of small squares. The snake is moving with the help of an illusion wherein the last square is brought to the front. This is built using a module pattern for code structure. A snake game is a simple game where a snake moves around a box trying to eat an apple. Once it successfully eats the apple, the length of the snake increases and the movement becomes faster. Then the game is over when the snake runs into itself or any of the four walls of the box.

Start with an empty HTML document and open it in Chrome.Insert the following code that just sets up a HTML document withstyle / script tags and a function to set up the game.

You can find the final code here and a live demo here. Getting Started. Let’s begin by creating a file “snake.html” that will contain all our code. Since this is an HTML file, the first thing we need is the

Let’s start from the top: The head tag. In here we have a title to put a documenttitle on the page, as well as a style tag containing styling to center the contentsof the page horizontally and change the font to a sans-serif one.

The the body element, which contains a h1 element with the title of the game anda single div element that will contain the game board. We have it tagged with the id ‘board’so we can access the element from JavaScript. We also have a script that will soon containall of our game logic.

The body element also has an onload handler, which calls the initGame functiondefined in the script tag. This means that once the document is completely loaded,the code inside initGame will run. There is nothing there yet, so lets’ get started!

Note: If you view the source code on all examples, there will be a script tag atthe bottom that handles integration with the iframe when the examples are included onthis page. You can inspect it if you like, but it is not necessary to understand it.

Creating the board

We’ll start out by creating the game board.

The board will be represented as a two-dimensional array, that is, an array of arrays.We create this as a constant variable inside the script tag called board, we alsodefine the width and height of the board with two constant variables. Here I havearbitrarily picked 26 by 16 cells (this is a convenient size to fit on screen).

To make it simple, we’ll build the entire board out of div elements, and will stylethese to look like cells, apples and the snake. We create these diivs by iterating overthe Y and X axes, creating columns and rows of items:

Each cell will be defined by an empty object {}. In this object we will put the state for each cell.

We need to fetch the board from the DOM (remember the <div?). Wedo this using document.getElementById and store it in a variable. This is done outsidethe loops.

For every cell, we create a div element on the board via document.createElement.Then we add this cell to the boardElement, meaning every cell will have a matching div in the DOM.

You can use the developer tools for Chrome to look at the document structure, and you willsee all the elements.

Finally, we need to store all these cells inside the board array of arrays.We do this by creating an array for every row, and pushing the cells intothis row in the inner loop, and every row into the board array for everyouter loop, giving us our final initGame function:

However, if you run this code, nothing will show up. This is because divelements by default are invisible, we need to give the some styling to makethem visible on the page.

To make the divs visible, we assign them a black background color, a width and aheight. We do this using CSS, by adding some code inside the <style> tag in the template.To style the cells we use the #board div selector. This targets all thediv elements inside the element with the id board.

If you try only this they will all lay out in a loooong column down the pagethat is 24 pixels wide. To fix this, we need to float the elements. This movesthem around so that there is not a line break after every element. Insteadthe page will now display as rows and columns of solid blocks.

The box-sizing property is necessary so that the width of the borders don’t make thecells wider than 24px. You can read up on box-sizing if you are curious about this.

If you view the above example, you will notice that the grid is not square,.We also need to limit the board in width, so that the grid is only 26 cellswide. We specify the width of #board to be 26 * 24px, and use the calcfunction in CSS to not have to calculate this number manually. The margin: automeans that the board will be centered horizontally on-screen.

We now have a black grid for the snake game!

It is not very interesting yet though, because we don’t have any snakeon the game board to control.

Keep track of the game state

Next we need to add the snake to the board. We start by defining the properties the snakehas in this game, there are a few:

Direction — The snake is moving either left, right, up or down. We can store this as strings 'Up', 'Down', 'Left' and ‘Right’.
Position — Defined as a X and Y position on the board. Note that 0, 0 will be top left on the board and 25, 15 will be bottom right.
Length — Length of the snake in segments.

Let’s create global variables for these properties:

We also need to store the tail of the snake. To keep track of this, we store the information about the tail in the board. So we’ll add a property snake to every cell on the board.

We’ll give it an integer value of 0 to denote that the snake is not on the space (at the start of the game).

Start the game

We also need to give some default values to the snake properties. We’ll do that in a new startGame function. This function will set all the properties to default values at the start of the game.

The snake will start moving upwards, with a length of 5 segments.It will start in the center of the board (divide width and height by 2), we need to use Math.floorhere to round down, since if the board width is 25, 12.5 is not a meaningful position on the grid.

Snake Game Codes For Notepad

Why create a new function for this? We could just use default values for global variables?The reason is we also need to do the same thing when the player dies to reset the game state, by putting it in a functi

Snake Game Html Code