Re: NEWBIE: Why use protocols?
Re: NEWBIE: Why use protocols?
- Subject: Re: NEWBIE: Why use protocols?
- From: Daniel Jalkut <email@hidden>
- Date: Wed, 18 May 2005 10:05:53 -0700
Also keep in mind that a protocol allows the method declarations to
stay in one place (the protocol definition) without requiring them to
be redundantly defined in each class that conforms to the protocol.
Consider your idea that you might as well just put the declarations
in the object. You could do that, but then if the protocol changes
in any way, you run the risk of having objects that are no longer
conforming but do not trigger any errors on build.
Daniel
On May 18, 2005, at 8:25 AM, Cameron Hayne wrote:
On 18-May-05, at 11:11 AM, Ben D. Jones wrote:
I don't get why or when the use of a protocol is a must for
clarity or function.
Protocols are useful when you have more than one class that you
want to use interchangeably in some circumstances. If you don't
care about what type of object is being handled as long as it
understands (implements) the "UpDown" protocol, then you can
declare a parameter as:
id <UpDown>
instead of restricting it to a specific class.
In this way, protocols are useful in circumstances where multiple
inheritance might be used in C++
--
Cameron Hayne
email@hidden
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
sweater.com
This email sent to email@hidden
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden