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Re: Sending a msg. to a class

Clearly, "z" has a situation where he declared a bunch of variables

SomeClass* pawn1;
SomeClass* pawn2;
.
.
.
SomeClass* pawn16;


and wants to iterate over them.

Unfortunately, "z" also thinks that Obj-C has some way to dynamically construct "references by name" to these objects (you can do this in JavaScript, for example).

I'm unaware of any scheme to get this JavaScript like idiom to work in Obj-C, certainly none that are as simple as just stuffing all those pawns in an array to begin with and iterating over that.

"z", you should probably spend some time with some of the introductory Objective-C docs out there.

_murat


On Oct 25, 2007, at 1:52 PM, Shawn Erickson wrote:

On 10/25/07, Glen Simmons <email@hidden> wrote: 
On Oct 25, 2007, at 2:35 PM, z wrote:


I'll appreciate someone to help me understand the problem and
suggest solution.
I'm trying to send a msg. to Pawn1 thru Pawn16 classes, but it
doesn't work from inside the loop.
Thanks.

- (IBAction)resetAll: (id)sender {

//    [toPawn1 showYourself];                 //--- This works fine.
//    .......
//    [toPawn16 showYourself];

/ but the following generates a warning: 'NSMutableString' may not
respond to '-showYourself'

for (i = 1; i <= 16; ++i) {
NSMutableString *str = [NSMutableString stringWithFormat: @"toPawn
%i", i];
[ [str className] showYourself];
[str release];
}
} 


1. You're not sending the showYourself method to the class, but to
the object that is returned from the -className message, which is an
NSString instance. That's why you're getting the warning. To get a
class object from an NSString, you need to use NSClassFromString
function.
2. You shouldn't release str, since you didn't alloc, retain or copy
it. See the docs on memory management.

NSString* className = [NSString stringWithFormat:@"toPawn%i", i];
Class theClass = NSClassFromString(className);
[theClass showYourself];


However it looks like showYourself is an instance method give what
little information has been posted so far... so I don't think the
above would do what he wants in the end.

-Shawn
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References: 
 >Sending a msg. to a class (From: "z" <email@hidden>)
 >Re: Sending a msg. to a class (From: Glen Simmons <email@hidden>)
 >Re: Sending a msg. to a class (From: "Shawn Erickson" <email@hidden>)



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