From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2013-07-27T20:59:02+09:00
Subject: Re: Calculate input - numbers

On Sat, Jul 27, 2013 at 1:44 PM, Marc Heiler <lists@ruby-forum.com> wrote:
> Hi
>
> user_input = $stdin.gets.chomp
>
> Now the user types:
>
> "5 + 5"
>
> As string (without the quotes).
>
> user_input is now a string object containing "5 + 5"
>
> I would like to give back the result of the operation, which should be
> 10.
>
> Right now I use eval() and it works, but I am wondering if there is a
> better alternative for it? How does IRB solve this?

IRB uses eval too. You can see it here:

https://github.com/ruby/ruby/blob/trunk/lib/irb/workspace.rb#L85

Jesus.