Inherits From:
NSObject
Conforms To:
NSCoding
NSCopying
NSObject (NSObject)
Declared in: EOControl/EONull.h
EONull has exactly one instance, returned by the null class method. This object isn't reference-counted, can't be copied (copyWithZone: returns self ), and is never deallocated. You can thus safely cache this instance and use pointer comparison to test for the presence of a null value:
static id NULL_VALUE;
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
/* ... */
NULL_VALUE = [EONull null];
return;
}
if (value == NULL_VALUE) {
/* ... */
}
Returns the unique instance of EONull.
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