Question about DQN inputs

[TheInvoker]

I am trying to understand the inputs for the example given here
http://cs.stanford.edu/people/karpathy/reinforcejs/index.html

env.getNumStates()
This is the size of the vector that represents the variables of the current game configuration?

env.getMaxNumActions
For this one, is it the total number of configurations the game can have? Or is it the number of actions the play can currently do in the current game configuration, such as in a grid maze, the player has up to 4 directions to move, so it would be 4.

Inside the "setInterval" function, "s" is not defined. It is the vector of the variables of the current game configuration that I have to get myself?

And "reward" is something I have to calculate too based on the current "s" vector?

Also why is getNumStates and getMaxNumActions a function, when they seem to return a constant value? Is it supposed to support returning dynamic values? Can the vector size be allowed to be different at anytime? And the Max num of actions, is that dynamic too?