From: Peter Szinek <peter@...>
Date: 2008-11-16T06:15:51+09:00
Subject: Re: Simple Question

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Hi,

> def deleted_roles=(values)
>  roles.find(*values).each(&:destroy)
> end
>
> I understand that this method finds all the roles with the given ids  
> and
> calls destroy on all of them. My question is, what is the significance
> of *. Why is it roles.find(*values) and not just plain
> roles.find(values)?
>
> Is there any difference?
>
> Could it possibly be a typo and the method should be defined as
>
> def deleted_roles(*values)...

It looks like roles.find expects a list of parameters (i.e. it should  
be invoked like this: roles.find('admin', 'user', 'editor'))
but deleted_roles= wants an array (i.e. deleted_rows = ['admin',  
'user', 'editor'])

The * a.k.a.  splat does exactly this conversion - so if someone calls

deleted_rows = ['admin', 'user', 'editor']

inside the method

  roles.find('admin', 'user', 'editor').each(&:destroy)

will be called (note that the brackets are gone)


HTH,
Peter
___
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