Check out Chris Pine's Book -- Learn to Program from the Pragmatic Programmers He has an English Number example in there:
http://pine.fm/LearnToProgram/?Chapter=08 def englishNumber number if number < 0 # No negative numbers. return 'Please enter a number that isn\'t negative.' end if number == 0 return 'zero' end # No more special cases! No more returns! numString = '' # This is the string we will return. onesPlace = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine'] tensPlace = ['ten', 'twenty', 'thirty', 'forty', 'fifty', 'sixty', 'seventy', 'eighty', 'ninety'] teenagers = ['eleven', 'twelve', 'thirteen', 'fourteen', 'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen'] # "left" is how much of the number we still have left to write out. # "write" is the part we are writing out right now. # write and left... get it? :) left = number write = left/100 # How many hundreds left to write out? left = left - write*100 # Subtract off those hundreds. if write > 0 # Now here's a really sly trick: hundreds = englishNumber write numString = numString + hundreds + ' hundred' # That's called "recursion". So what did I just do? # I told this method to call itself, but with "write" instead of # "number". Remember that "write" is (at the moment) the number of # hundreds we have to write out. After we add "hundreds" to "numString", # we add the string ' hundred' after it. So, for example, if # we originally called englishNumber with 1999 (so "number" = 1999), # then at this point "write" would be 19, and "left" would be 99. # The laziest thing to do at this point is to have englishNumber # write out the 'nineteen' for us, then we write out ' hundred', # and then the rest of englishNumber writes out 'ninety-nine'. if left > 0 # So we don't write 'two hundredfifty-one'... numString = numString + ' ' end end write = left/10 # How many tens left to write out? left = left - write*10 # Subtract off those tens. if write > 0 if ((write == 1) and (left > 0)) # Since we can't write "tenty-two" instead of "twelve", # we have to make a special exception for these. numString = numString + teenagers[left-1] # The "-1" is because teenagers[3] is 'fourteen', not 'thirteen'. # Since we took care of the digit in the ones place already, # we have nothing left to write. left = 0 else numString = numString + tensPlace[write-1] # The "-1" is because tensPlace[3] is 'forty', not 'thirty'. end if left > 0 # So we don't write 'sixtyfour'... numString = numString + '-' end end write = left # How many ones left to write out? left = 0 # Subtract off those ones. if write > 0 numString = numString + onesPlace[write-1] # The "-1" is because onesPlace[3] is 'four', not 'three'. end # Now we just return "numString"... numString end puts englishNumber( 0) puts englishNumber( 9) puts englishNumber( 10) puts englishNumber( 11) puts englishNumber( 17) puts englishNumber( 32) puts englishNumber( 88) puts englishNumber( 99) puts englishNumber(100) puts englishNumber(101) puts englishNumber(234) puts englishNumber(3211) puts englishNumber(999999) puts englishNumber(1000000000000) -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-t...@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
