From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2009-08-14T06:29:48+09:00
Subject: Re: New to ruby - how can I take this further?

On Thu, Aug 13, 2009 at 10:56 PM, Stuart Cullum<stuart.cullum@gmail.com> 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.