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This is probably easy to do! I'm not able envision the loop yet, I was thinking about a nested for loop but not quite sure how to alternate between the two hashes.

Lets say I have a class with a def that containts two hash tables:

 class Teststuff
    def test_stuff
     letters = { "0" => " A ", "1" => " B ", "2" => " C " }
     position = {"1" => "one ", "2"=> " two ", "3"=> " three ", "4"=>" four " }

     my_array=[0,1,2,2] #this represents user input stored in an array valid to 4 elements
     array_size = my_array.size #this represents the size of the user inputed array
     element_indexer = my_array.size # parellel assignment so I can use same array for array in dex
     array_start_index = element_indexer-1 #give me the ability later to get start at index zero for my array

 #for loop?? downto upto?? 
 # trying to get loop to grab the first number "0" in element position "0", grab the hash values then
 # the loop repeats and grabs the second number "1" in element position "1" grab the hash values
 # the loop repeats and grabs the third number "2" in elements position "2" grab the hash values
 # the final iteration grabs the fourth number "2" in elements position "3" grab the hash values
 # all this gets returned when called. Out put from puts statement after grabing hash values 
 # is: **A one B two C three C four**  

     return a_string
    end
  end

How do I go about returning string output to the screen like this: 

   **A one B two C three C four**

or simply letter position letter position... Thanks for the help, put code up so I can try on my editor!

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  • It's very hard to understand what you are trying to do. What does my_array do? It doesn't seem to be used in your code anywhere. The same for array_size, element_indexer and array_start_index. Where does a_string come from? What are letters and position used for? They aren't used anywhere, either! (In fact, none of your variables are used anywhere.) What is the class Teststuff for? It never gets instantiated. What is the method test_stuff for? It never gets called. Can you provide testcases for what the output should be? Commented Nov 26, 2010 at 11:34
  • At the moment, there are no parameters, so the output will always be the same, in which case you might just as well do return '**A one B two C three C four**'. Which reminds me: why is the output **A one B two C three C four** and not **A one B two C three C three** or **A one B two C three D four**? Commented Nov 26, 2010 at 11:36
  • Also, why is letters a Hash and not an Array and why do letters and position use String s for the keys instead of Integer s or the other way around, why does my_array use Integer s for the values, and not String s? Why are there spaces around the letters in letters but not in the output? Same for position? Commented Nov 26, 2010 at 11:41
  • edited to explain a little better. To answer comments from above: Commented Nov 26, 2010 at 17:23
  • To answer comments from above: 1. my_array is user input, array_size is a variable I set up to be able to get the .size of my_array. Element_indexer is used for parallel assignment so I can use the variable in array_start_index. Array_start_index is used to determine element position for the loop I don't know how to utilize quite yet. Never instantiated or used method as I left it open for looping examples. Simple puts statment like puts x.a_string. Commented Nov 26, 2010 at 17:39

3 Answers 3

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1

I think I figured out what it is you want, although I still have no idea what array_size, element_indexer, array_start_index and TestStuff are for.

def test_stuff
  letters = { "0" => " A ", "1" => " B ", "2" => " C " }
  position = {"1" => "one ", "2"=> " two ", "3"=> " three ", "4"=>" four " }

  my_array = [0, 1, 2, 2]

  "**#{my_array.map.with_index {|e, i|
    "#{letters[e.to_s].strip} #{position[(i+1).to_s].strip}"
  }.join(' ')}**"
end

[I took the liberty of reformatting your code to standard Ruby coding style.]

However, everything would be much simpler, if there weren't all those type conversions, and all those superfluous spaces. Also, the method would be much more useful, if it actually had a way to return different results, instead of always returning the same thing, because at the moment, it is actually exactly equivalent to

def test_stuff
  '**A one B two C three C four**'
end

Something along these lines would make much more sense:

def test_stuff(*args)
  letters = %w[A B C]
  position = %w[one two three four]

  "**#{args.map.with_index {|e, i| "#{letters[e]} #{position[i]}" }.join(' ')}**"
end

test_stuff(0, 1, 2, 2)
# => '**A one B two C three C four**'

If you don't want to pollute the Object namespace with your method, you could do something like this:

def (TestStuff = Object.new).test_stuff(*args)
  letters = %w[A B C]
  position = %w[one two three four]

  "**#{args.map.with_index {|e, i| "#{letters[e]} #{position[i]}" }.join(' ')}**"
end

TestStuff.test_stuff(0, 1, 2, 2)
# => '**A one B two C three C four**'
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2 Comments

+1 for assigning a method on an object which is itself the result of an expression -- that's a neat trick.
@zetetic: I use that when I want to bundle a couple of "procedures" together into a single namespace. A lot of people use a module with only singleton methods for that case, but I think modules are for including, not for bundling methods. If you want a singleton object to hold a bunch of loosely related methods, why not use a singleton object?
1

You can use enumerators, like this:

l = letters.to_enum
p = position.to_enum
a_string = ''
loop do
  a_string << l.next[1] << p.next[1]
end
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0

How about :

a_string = ""
my_array.each_with_index { |x, index|
  a_string += letters[my_array[index].to_s] + " " + (position.include?((index+1).to_s) ? position[(index+1).to_s] : "nil")
}
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