How do I pass multiple parameters in Objective-C?

Question

I have read several of the post about Objective-C method syntax but I guess I don't understand multiple names for a method.

I'm trying to create a method called getBusStops with NSString and NSTimeInterval parameters and a return type of NSMutableArray. This is how I have constructed the method but it obviously gets errors at runtime:

- (NSMutableArray *)getBusStops:(NSString *)busStop
                                (NSTimeInterval *)timeInterval;

I saw another example with a method:

-(NSInteger)pickerView:(UIPickerView *)pickerView
            numberOfRowsInComponent:(NSInteger)component

I don't understand why this method has a method name for each parameter. Should I do the same with something like:

- (NSMutableArray *)getBusStops:(NSString *)busStop
                        forTime:(NSTimeInterval *)timeInterval

Answer 1

You need to delimit each parameter name with a ":" at the very least. Technically the name is optional, but it is recommended for readability. So you could write:

- (NSMutableArray*)getBusStops:(NSString*)busStop :(NSSTimeInterval*)timeInterval;

or what you suggested:

- (NSMutableArray*)getBusStops:(NSString*)busStop forTime:(NSSTimeInterval*)timeInterval;