# New to ruby - how can I take this further? **URL:** \ **Category:** Ruby\ **Created:** [August 13, 2009, 10:56pm UTC](https://www.ruby-forum.com/t/new-to-ruby-how-can-i-take-this-further/173729 "2009-08-13T22:56:48Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![stooz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e47774/32.png) [@stooz](https://www.ruby-forum.com/u/stooz)\ **Post date:** [August 13, 2009, 10:56pm UTC](https://www.ruby-forum.com/t/new-to-ruby-how-can-i-take-this-further/173729/1 "2009-08-13T22:56:48Z")
Hi all I’m new to programming, and new to Ruby. I’ve written a little program listed below, a very simple math test, to get into the swing of things. My question; could someone point out what I could do to make this more elegant, and any mistakes etc. - basically a critique would be most welcome. I think this would give me some real help in understanding what I need to learn next. Many thanks for your time s. puts “Please enter your name:” firstname = gets.chomp number1 = rand(100) number2 = rand(100) operatorarray = ["+", “-”] randop = rand(2) getoperator = operatorarray[randop] question = number1.to\_s + getoperator + number2.to\_s answer = eval “#{number1} #{getoperator} #{number2}” puts “Welcome to MathTest!” puts “#{firstname}” + “, here is your first question:” puts question usranswer = gets.chomp if eval “#{usranswer} == #{answer}” puts “Correct!” else puts "Incorrect. The answer is " + “#{answer}” end ---
**Author:** ![stooz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e47774/32.png) [@stooz](https://www.ruby-forum.com/u/stooz)\ **Post date:** [August 13, 2009, 11:30pm UTC](https://www.ruby-forum.com/t/new-to-ruby-how-can-i-take-this-further/173729/2 "2009-08-13T23:30:41Z")
On Thu, Aug 13, 2009 at 10:56 PM, Stuart Cullum[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hi all > > I’m new to programming, and new to Ruby. > > I’ve written a little program listed below, a very simple math test, to > get into the swing of things. > > My question; could someone point out what I could do to make this more > elegant, and any mistakes etc. - basically a critique would be most > welcome. This is how I’d do it straight away from your code: puts “Please enter your name:” first\_name = gets.chomp number1 = rand(100) number2 = rand(100) # I’d use symbols for the operators # also note the snake\_case convention operator\_array = [:+, :-] #removed some unnecessary variables operator = operator\_array[rand(2)] # Cleaner (IMHO) with string interpolation, # no need for .to\_s question = “#{number1} #{operator} #{number2}” # We know the operators are methods of the numbers # so I’d rather send the method than eval a string answer = number1.send(operator, number2) puts “Welcome to MathTest!” # String interpolation rather than concatenation puts “#{first\_name}, here is your first question:” puts question # get the answer as an integer user\_answer = gets.chomp.to\_i #no need to eval here, just compare the ints if user\_answer == answer puts “Correct!” else puts "Incorrect. The answer is " + “#{answer}” end The next step could be to put the questions in a loop, so you don’t need to type your name every time, and to count correct/incorrect answers and show a summary. Further, you could extend this to save to a file a count of correct/incorrect answers by name, and load this data at start and update it with the new session of answers. Good luck ! Jesus. ---
**Author:** ![stooz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e47774/32.png) [@stooz](https://www.ruby-forum.com/u/stooz)\ **Post date:** [August 13, 2009, 11:37pm UTC](https://www.ruby-forum.com/t/new-to-ruby-how-can-i-take-this-further/173729/3 "2009-08-13T23:37:18Z")
> Good luck ! > > Jesus. Jesus Thanks very much for your time. I will go and attempt a new version! Best regards s. ---
**Author:** ![stooz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e47774/32.png) [@stooz](https://www.ruby-forum.com/u/stooz)\ **Post date:** [August 14, 2009, 11:45pm UTC](https://www.ruby-forum.com/t/new-to-ruby-how-can-i-take-this-further/173729/4 "2009-08-14T23:45:12Z")
On Fri, Aug 14, 2009 at 6:25 PM, Fabian Streitel[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > operator\_array = [:+, :-] > > I personally prefer %w: > > operator\_array = %w{+ -} > > Especially when you get more entries, %w helps you save time and maintain > readability. I use %w a lot, when I want Strings. In this case though, my preference is to use symbols, because they represent better what they are used for in this program. > > puts "Incorrect. The answer is " + “#{answer}” > you missed one! 🙂 Yep, good catch 🙂 Cheers, Jesus. ---
**Author:** ![stooz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e47774/32.png) [@stooz](https://www.ruby-forum.com/u/stooz)\ **Post date:** [August 14, 2009, 6:26pm UTC](https://www.ruby-forum.com/t/new-to-ruby-how-can-i-take-this-further/173729/5 "2009-08-14T18:26:47Z")
just some more suggestions: puts “Please enter your name:” > first\_name = gets.chomp > > number1 = rand(100) > number2 = rand(100) > > # I’d use symbols for the operators > > # also note the snake\_case convention > > operator\_array = [:+, :-] I personally prefer %w: operator\_array = %w{+ -} Especially when you get more entries, %w helps you save time and maintain readability. Basically, what it does is, it splits the string in between the {} at every whitespace and returns an Array containing the Strings inbetween the whitespace. #removed some unnecessary variables > operator = operator\_array[rand(2)] > > # Cleaner (IMHO) with string interpolation, > > # no need for .to\_s > > question = “#{number1} #{operator} #{number2}” > > # We know the operators are methods of the numbers > > # so I’d rather send the method than eval a string > > answer = number1.send(operator, number2) Also, you should steer clear of eval, since it is quite a security risk. Users could give you any Ruby code, even stuff that deletes files etc. I’ve found that most of the time you can get rid of it. puts “Welcome to MathTest!” > else > puts "Incorrect. The answer is " + “#{answer}” you missed one! 🙂 puts “Incorrect. The answer is #{answer}” > end Keep it up! Hope you have lots of fun with Ruby! Greetz!