Ruby Programming Language :: How to improve iteration


	How to improve iteration Hi, Could you please point out how I can make this code more compact/cleaner/smarter??? Gotta be a block..I just don't see how to connect it. Gratefully, Chas <------Switch File Names---> ar = ["a.txt", "b.txt", "c.txt", "d.txt", "e.txt"] br = ["first.txt", "second.txt", "third.txt", "fourth.txt", "fifth.txt"] length = ar.length class FileNameSwap def switch( letters, ordinals, length) for i in 0..length -1 if File.file?(letters[i]) File.rename(letters[i], ordinals[i]) puts "switched to ordinal" else File.rename(ordinals[i], letters[i]) puts "switch to letter" end end end end switcher = FileNameSwap.new switcher.switch(ar,br, length) <---end----> -- Posted via http://www.ruby-forum.com/. Instead of doing for...in and use i as an index, you could do letters.each...do...\|letter\| and there's no index. letter is the extracted index. The only problem would be the ordinals[i] which could stay as it is and note your own iterations (not recommended) or do, instead of letters.each, do letters.each_index do \|i\| and little would change. Both suggestions would rid you of needing the length argument, but to be honest that's the only real disadvantage to your algorithm. It's pretty much fine how it is. You should only change it if it's really hard to find length in my opinion. Chas Conquest wrote: > Could you please point out how I can make this code more > compact/cleaner/smarter??? I'll try: ar = ["a.txt", "b.txt", "c.txt", "d.txt", "e.txt"] br = ["first.txt", "second.txt", "third.txt", "fourth.txt", "fifth.txt"] class FileNameSwap # I don't know why you chose to make a class for this, but since you did I'll # at least store the arrays as instance variables def initialize(letters,ordinals) @letters=letters @ordinals=ordinals end def switch @letters.zip(@ordinals).each do \|letter, ordinal\| if File.file? letter File.rename(letter, ordinal) else File.rename(ordinal, letter) end end end end switcher = FileNameSwap.new(ar,br) switcher.switch HTH, Sebastian Hungerecker -- NP: Sentenced - Blood & Tears Ist so, weil ist so Bleibt so, weil war so Fantastic guys! Thanks very much. -- Posted via http://www.ruby-forum.com/. On 28.05.2007 19:47, Sebastian Hungerecker wrote: - Hide quoted text - > Chas Conquest wrote: >> Could you please point out how I can make this code more >> compact/cleaner/smarter??? > I'll try: > ar = ["a.txt", "b.txt", "c.txt", "d.txt", "e.txt"] > br = ["first.txt", "second.txt", "third.txt", "fourth.txt", "fifth.txt"] > class FileNameSwap > # I don't know why you chose to make a class for this, but since you did I'll > # at least store the arrays as instance variables > def initialize(letters,ordinals) > @letters=letters > @ordinals=ordinals > end > def switch > @letters.zip(@ordinals).each do \|letter, ordinal\| > if File.file? letter > File.rename(letter, ordinal) > else > File.rename(ordinal, letter) > end > end > end > end > switcher = FileNameSwap.new(ar,br) > switcher.switch And a strange variant of this: def switch(letters, ordinals) letters.zip(ordinals).each do \|a\| File.rename((File.file? a[0] ? a : a.reverse)) end end :-) robert PS: Sorry to all who expected an #inject solution. ;-)