Trying to get symbols that are stored in a hash into an array, help needed.

**Tical** · Jun 4, 2007 04:20

Hey guys I'm pretty new to Ruby and programming in general. I'm reading the Ruby book "Beginning Ruby - From Novice To Professional" and I'm doing one of the included projects - building a basic text adventure.

I'm done with the text adventure but now I want to expand the features with some of my own methods but I'm running into problems.

What I want to do is to have a method that prints out in which directions (south, north, east, west), from any given room, there are exists to other rooms.

To do this I want to iterate through a hash with the each method and store every key (not value) in an array so that I then can see how many exits there are to the room where the player is at and print out a message of those exits. The keys are symbols.

So I've come this far:

Code Ruby:

def find_exits
  find_room_in_dungeon(@player.location).connections.each {|direction, location| }
end

This part

Code Ruby:

 find_room_in_dungeon(@player.location)

finds the current room object where the player is at.

This is the Room class:

Code Ruby:

class Room
 
      #Creates the objects variables that store infromation about the Room.
      attr_accessor :reference, :name, :description, :connections
 
      #Sets the information that is set when the object is created to the object variables for storage.
      def initialize(reference, name, description, connections)
         @reference = reference
         @name = name
         @description = description
         @connections = connections
      end
 
      #Defines a method that returns the full description of the Room object. 
      def full_description
       @name + "\n\nYou are in " + @description
      end
   end

@connections is a object variable that stores the hash that contains directions and locations like so for example: {:east => :large_room}

So I managed to store the directions of any given Room object with this line:

Code Ruby:

 find_room_in_dungeon(@player.location).connections.each {|direction, location| }

but how do I get what's in direction into an array?

I have no idea how to do this. Any help is appreciated.

**Fenrir2** · Jun 4, 2007 08:38

You can do it like this:

Code Ruby:

directions = []
 
find_room_in_dungeon(@player.location).connections.each do |direction, location|
  directions << direction
end

But this is better:

Code Ruby:

directions = find_room_in_dungeon(@player.location).connections.keys

Hash#keys returns all keys present in the hash.

**Tical** · Jun 4, 2007 11:53

Thanks a lot I got it working! That's exactly what I needed.

And btw it is okay to ask general Ruby questions here, I mean it's not only a RoR forum, right?

**Tical** · Jun 4, 2007 13:11

Ok so I need some more help if that's ok.
This is how it looks so far:

Code Ruby:

 def find_exits
      directions = find_room_in_dungeon(@player.location).connections.keys
 
      if directions.length == 1
       puts "You see an exit to your " + directions[0].to_s
      elsif directions.length == 2
       puts "You see exits to your " + directions[0].to_s + " and to your " + directions[1].to_s
      else
         print "You see exits to your"
         directions.each {|direction| print " " + direction.to_s + ","} 
      end
 
   end

It works good when the room has one or two exits for example:

Code Ruby:

d.add_room(:large_room, "Large room", "a large, empty room used for unknown purposes", {:west => :hallway})

produces this when find_exits is run: "You see an exit to your west"

Now the problem is when there's more then 2 directions. As you can see in the code when there's more then 2 objects in the directions array this is executed:

Code Ruby:

print "You see exits to your"
directions.each {|direction| print " " + direction.to_s + ","}

This isn't ideal beacuse it just prints the directions with a comma afterwards. On one room object I have the output is this: "You see exits to your west, north, eats,"

I want it to print "You see exits to your west, north and east" but I can't figure out how to do that unless I code one separate elsif for every possible number of directions, and that's not a good way.
Is there some way I can get that output and still use an interator?

**Fenrir2** · Jun 5, 2007 11:33

I'd do it this way:

Code Ruby:

def array_in_words(array)
  case array.length
  when 1: array.first.to_s
  when 2: "#{array[0]} and #{array[1]}"
  else array[0..-3].join(", ") + ", #{array[-2]} and #{array[-1]}"
  end
end
 
array_in_words(["one"]) # => "one"
array_in_words(["one", "two"]) # => "one and two"
array_in_words(["one", "two", "three"]) # => "one, two and three"