From: Robert Klemme <shortcutter@...>
Date: 2007-12-16T21:55:00+09:00
Subject: Re: How t owrite an OR statement

On 16.12.2007 07:18, Daniel Peikes wrote:
> Joseph Pecoraro wrote:
>>> while again != "y" || "n"
>>
>> These don't use the OR logic, but they are similiar.
>> until again ~= /^[yn]/i do
>>   ...
>> end
>>
>> Or if your wanted to keep the while keyword you could do this as:
>> while again[0] != /^[^yn]/i do
>>   ...
>> end
>>
>>
>> I don't know if you can do exactly what you are trying to do with that 
>> syntax.  You can reconstruct the logic like this:
>> while again != "y" && again != "n" do
>>   ...
>> end
>>
>>
>> Here is another approach more along the lines of what you have (is 
>> something in a list of something else), likewise the until loop could be 
>> made a while loop:
>> good_chars = %w(y n) #=> ['y', 'n']
>> until good_chars.include? again do
>>   ...
>> end
> 
> This is what I currently have, but it looks to be giving me an infinite 
> loop:
> again = "y"
> number = []
> 
> while  again == "y"
> 
> 
>   puts "Please enter a number."
> 
>   number = gets.chomp
> 
>   puts "Would you like to enter a number again? y/n"
> 
>   again = gets.chomp.downcase
> 
>   while again != "y" or "n"
> 
>     puts "Would you like to enter a number again? y/n"
> 
>   end
> 
> end
> 
> puts number
> 
> hold = gets

Your logic will become easier if you use post checked loops:

numbers = []
again = nil

begin
   puts "Please enter a number."
   numbers << Integer(gets)

   begin
     puts "Would you like to enter a number again? y/n"
     again = gets.chomp.downcase
   end until again == "y" || again == "n"
end while again == "y"

puts numbers

With regard to "or": "or" has a much lower precedence than "||" so it is 
usually better in conditions like these to use "||".

Kind regards

	robert