2 questions about my array/range

Okay, so I wrote a script that’ll allow the game player to jump with the
touch of a button. This script, I wanted a method that’ll adjust the
distance in which
the game player jumps, based on the farthest passible tile. To define
the method, I used a ‘for i’ statement with 0 to the max distance, for
each passible ‘space’ he can jump, I push the value into an array named
@spaces’, respectively.

def jump_dist @spaces = [] case @direction when 2 # Down for i in 0...Jump::Distance if passable?(self.x, self.y + i, 2) @spaces[i] = i return @spaces if i == Jump::Distance end end when 4 # Left for i in 0...Jump::Distance if passable?(self.x - i, self.y, 4) @spaces[i] = i return @spaces if i == Jump::Distance end end when 6 # Right for i in 0...Jump::Distance if passable?(self.x + i, self.y, 6) @spaces[i] = i return @spaces if i == Jump::Distance end end when 8 # Up for i in 0...Jump::Distance if passable?(self.x, self.y - i, 8) @spaces[i] = i return @spaces if i == Jump::Distance end end end end

…Maybe I wrote that a little oddly, correct me if you know a better
functional method.

Anyways, next I test it with ‘print(jump_dist)’ whenever the player
‘jumps’ and it returns 0…3 (3 is Jump::Distance, BTW)

So basically, instead of returning an array, it returns a Range.

How do I get this to return me an array of only passable ‘spaces’, and
secondly how do I pull the highest value out of that array?

Hi –

On Wed, 16 Jul 2008, Kain Nobel wrote:

case @direction
@spaces[i] = i
when 8 # Up
functional method.
Well, here’s an untested rewrite that might save some space:

def jump_dist
spaces = []

 0.upto(Jump::Distance-1) do |i|
   pass = case @direction
          when DOWN   then passable?(self.x, self.y + i, 2)
          when LEFT   then passable?(self.x - i, self.y, 4)
          when RIGHT  then passable?(self.x + i, self.y, 6)
          when UP     then passable?(self.x, self.y - 1, 8)
          end
   if pass
     spaces[i] = i
   end
 end

 return spaces

end

(I’ve turned @spaces into spaces, which is better unless you really
need it as an instance variable.)

Anyways, next I test it with ‘print(jump_dist)’ whenever the player
‘jumps’ and it returns 0…3 (3 is Jump::Distance, BTW)

So basically, instead of returning an array, it returns a Range.

How do I get this to return me an array of only passable ‘spaces’, and
secondly how do I pull the highest value out of that array?

The reason it’s returning a range is that your range is exclusive. The
range (0…Jump::Distance) doesn’t include Jump::Distance. Therefore,
the return statements never get executed. So what’s returned, instead,
is the value of the whole for statement, which is the range itself.

To get the last element of an array: array[-1].

David

Cool, that works wonders! Thanks David! Adds special thanks to David in
credit

I tried posting this in another forum and everybody wanted me to copy
someone else’s script!

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