On Nov 28, 2008, at 11:41 PM, Mikael Wämundson wrote:

-(NSString *) numberOfStudents
{
return [NSString stringWithFormat:@"The number of students is: %@", [theStudentArrayController valueForKeyPath:@"[EMAIL PROTECTED]"]];
}


I think that it would be more straight forward and efficient to write that:

[NSString stringWithFormat:@"The number of students is: %lu", ((unsigned long)[theStudentArrayController count])];


No error during compilation or run-time, but value in the text label is not updated when the array is changed.


That's because you haven't told the bindings machinery that the "numberOfStudents" property depends on the count of objects in the array. See:

<http://developer.apple.com/documentation/Cocoa/Conceptual/KeyValueObserving/Concepts/DependentKeys.html >


j o a r


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