Issue with the first Phaser.js tutorial

[pollofritto]

Hi guys,

i'm completely new to Phaser (to be honest i'm completely new to javascript as well  ) i started a tutorial found on the web which is going to teach me how to build an "old nokia style" snake game.

 

i had no problems at all following the beginning of the tutorial but at some point i got an error calculating the position/movement of the snake (the snake is an array). i really can't figure out what is happening. I also tried to copy/paste the tutorial .js files (from the chrome dev console actually in order to avoid some syntax mistake on tutorial itself... the tutorial provides a preview of the game for every steps) but the error is still there while the tutorial preview is doing amazing!

 

the error i got is this one: Uncaught TypeError: Cannot read property 'x' of undefined

 

this is the code:

firstCell = snake[snake.length - 1],lastCell = snake.shift(),oldLastCellx = lastCell.x,oldLastCelly = lastCell.y;

the issue is snake.shift() . It becomes undefined at some point.

i also think that the debug breaks something because if i try to debug the tutorial preview i got the same error i got on my code!!!!

 

this is the folder where you can find the folder of my project

 

https://www.dropbox.com/home/Phaser/phaser_test

 

 

i hope you can help me!

thanks.

 

 

 

 

[rich]

I don't have time to go through your code, but I suspect the array becomes empty at some point, causing the error. You can guard against this by checking the array length before you shift it. But I suspect that will just hide a deeper bug, as a snake 'body array' should never become empty really (as the snake only ever gets longer).

[pollofritto]

Uaaaa thank you rich! you mede me think when you say: the snake should never become empty... i made a couple of changes to my code.

The error is gone! the snake still does not move like it should be but it's better than before.. at least i am learning something 

 

well.. it was my code obviously..