It seems to be what's called a dictionary, where you have key:value pairs. So, if you show the key, you'll get back the value. E.g. socks = {red:3, blue:4, wh

It seems to be what's called a dictionary, where you have key:value pairs. So, if you show the key, you'll get back the value. E.g. socks = {red:3, blue:4, white:0} Print "how many red socks left? " & socks.red => how many red socks left? 3 In Javascript, you use an Object as dictionary. So, basically, the value for the key is set. Not "0th row, 1st column". After that, the case switching for the appropriate pressed key happens. X and Y directions of the screen are to be seen from the top Left corner (0/0). So when you want your snake to go up you have to reduce Y by step from the actual Y value (thus inputDir.y = -1;) InputDir is an key/value storage and get updated with the up/down/left/right step value (add 1 or minus 1 in x or y direction). This after, the InputDir will be checked constantly by the position setter or some drawing logic in a loop. Snake at 10/10 and needs to go to the right: 11/10 12/10 13/10 Then go down: 13/11 13/12 13/13 And back to the left: 12/13 11/13 10/13 Hacker News isn't the suitable place to ask thus kind of questions. I don't think you'll get another answer for your question. Please use the search engine of your choice to find appropriate places for question/answer. For example stack overflow. Or a tons of others:) Cheers,