From: Abder-Rahman Ali <abder.rahman.ali@...>
Date: 2010-07-13T23:50:08+09:00
Subject: Re: Errors in Ruby

Lars Olsson wrote:
> On 13 Juli, 14:07, Abder-Rahman Ali <abder.rahman....@gmail.com>
> wrote:
>> In the following sentence: The raise method is from the Kernel module.
>> By default, raise creates an exception of the RuntimeError class. From:http://rubylearning.com/satishtalim/ruby_exceptions.html
>>
>> What is meant by raising an exception of the "RunTimeError"? And, if we
>> raise it on "ArgumentError", what is mean by that?
>>
>> Thanks.
>> --
>> Posted viahttp://www.ruby-forum.com/.
> 
> Hi,
> 
> Exceptions are just regular classes in ruby. You can create your own
> or use the multitude of built in Exceptions.
> 
> Exception are usually very simple classes. The reason why you might
> need more than one is differentiation. Sometimes things can go wrong
> in more than one way.
> 
> begin
>   # Do stuff that raises an exception
> rescue MyFirstException => err
>   puts "MyFirstException occurred"
> rescue MySecondException => err
>   puts "MySecondException occurred"
> end
> 
> Usually you can distinguish what an exception is supposed to represent
> by its name. RunTimeError is a kind of catch-all error, you can trap
> almost every "normal" error using this exception class. An
> ArgumentError on the other hand is more specific and is raised when
> you try to call methods using the wrong number or type of arguments.
> 
> def foo(x, y)
>   puts x, y
> end
> 
> foo(3) => raises ArgumentError
> 
> /lasso

Thanks for your reply.

I just want to ask a thing since I'm new to Ruby.

When you say: rescue MyFirstException => err

How do you read this =>

Thanks.
-- 
Posted via http://www.ruby-forum.com/.