CODEWITHSUNDEEP
objective-ccocoapointers
joels
joels

Reputation: 7721

objective c id *

I am using the KVO validations in my cocoa app. I have a method

- (BOOL)validateName:(id *)ioValue error:(NSError **)outError

My controls can now have their bindings validate. How do I invoke that method with a id * NOT id

To use the value that is passed in (a pointer to a string pointer) I call this:

NSString * newName = (NSString *)*ioValue;
if ([newName length] < 4) {

otherwise i get bad exec crashes...

passing in with type casting doesnt work: (id *)myStringVar

passing in with a regular id doesnt work either : (id) myStringVar

Upvotes: 1

Views: 755

Answers (1)

Rob Napier
Rob Napier

Reputation: 299355

NSError *error;
[self validateName:&myStringVar error:&error];

The ampersand means "address of." In this case, it is the address of the pointer, or in other words, a pointer to a pointer (which is what an id* is).

Upvotes: 5

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