From: sto.mar@...
Date: 2013-04-12T02:16:57+09:00
Subject: Re: confusion with gets, if

Am 11.04.2013 17:16, schrieb Daniel ferrando:
> hi I'm new to ruby and im trying to write some simple codes but i cant
> get the 'if's to work. below what i mean. how can i fix the ruby code
> for the ifs to work?
>
> no matter what i write it always returns "invalid input"
> ##################Code#########################
> while counter < 1 do
>    print ("put 10, 20 or 30 ")

here, the extra space is not a problem, but you should use

   print("put 10, 20 or 30 ")

or simply: print "put 10, 20 or 30 "

>    input = gets()
>    if input == '10'

The source of the problem can be seen here:

   2.0.0-p0 :001 > input = gets
   10
    => "10\n"

the returned string contains an new line character!

possible solutions:

1.  input = gets.chomp  # the parentheses are not needed
     if input == '10'
       ...

2.  input = gets
     if input == "10\n"  # mind the double quotes!
       ...

And: it's always good practice to try code using IRB.

>      person1 += 1
>      counter += 1
>    elsif input == 20
>      person2 += 1
>      counter += 1
>    elsif input == 30
>      person3 += 1
>      counter += 1
>    else
>      puts("Invalid input")
>    end
>
>
> end
> ##############################################

As mentioned in a different post you would need strings
for 20 and 30, too.

> if i were to write it in python i would do it somewhat like this:
>
> ##################Code#########################
> while counter < 5 :
>
>      vector.append(input('put 10, 20 or 30 '))
>
>      if vector [counter] == '10' :
>          p1 += 1
>          counter += 1
>      elif vector [counter] == '20':
>          p2 += 1
>          counter +=1
>      elif vector [counter] == '30':
>          p3 += 1
>          counter += 1
>      else:
>          print ("invalid input")
>
> ##############################################

I'm not exactly sure what you are trying to do, but I don't care
much for the while loop and all the counters.

> last question whats the difference between ruby and ruby on rails?

Rails is a web framework written in Ruby, maybe comparable to Django
in the Python world.


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