Method with multiple input parameters

Question

I understand how to create my own methods that accept input parameters in objective-c but I have never actually created a method with more than one input parameter!

From methods I have used with multiple input parameters each has a name along the lines of

first:second:third:

and look like

- (void)first:(NSString *)fname second:(NSString *)mname third:(NSString *)lname;

my question is when creating your own method with multiple input parameters do you have to create a name like first:second:third or can you just have something like C++ where you have the one name followed by a list of input parameter types followed by the parameter names... if I remember correctly.

fullName:(NSString, NSString, NSString) fname, mname, lname; 

Answer 1

No. A method must have the format as you described:

- (void)first:(NSString *)fname second:(NSString *)mname third:(NSString *)lname; 

Answer 2

You have to have the parameters interleaved with the method signature. It's ok because xcode has code completion and it can give you nice descriptive names about what your method is doing and what it requires.

e.g.

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration 

In the example above without even looking at the API for UIViewController you can get a pretty good understanding of how this method works and what it's params are. It is good practice to name your methods well to describe what they do (it can remove the need for most commenting if done well).

You may well of course see a method written like this

- (void)myMethodThatAcceptsARectangle:(float)x :(float)y :(float)w :(float)h; 

But this will not be very clear in use as to what the parameters relate to:

[self myMethodThatAcceptsARectangle:1.0f :1.0f :1.0f :1.0f]; 

So you should avoid this (I added it incase you ever see this and wonder what's happening).