I taught a quick class on how objective C selectors work

Quick_Selectors_Overview.txt

objective-c selectors: 

SEL 

The alternative to blocks.
This is how delegate/protocol patterns work. (another talk)
Most common API is for UIButtons / UIControls
[button addTarget:self action:@selector(aMethod:) forControlEvents:UIControlEventTouchDown];
-(void)aMethod:(UIButton*)sender
Calls the selector on the target. 

A selector is it's own type SEL: 

SEl selector = @selector(aMethod)
 ^ notice no * because it's not a pointer

objc uses a integer to store the method name
@selector(aMethod) ---at runtime---> 72388763

Must be done at runtime because objective c is a dynamic language: implementations of functions can be changed while the applicaiton is running using a method called Swizzling (another talk)
So how is a method sent in objective-c? 
	[object method:parameter] could also be written as [target selector:parameter]	

	[joe performSelector:@selector(sayHelloToPerson:) withObject:bill];

we can also check if a class implments a method with: 
	[joe respondsToSelector:methodToCall]

And what it means for properties: 
	All properties are accessed via selectors on getter methods on functions. 
	@property (nonatomic) NSString *nonatomicString;
	creates getNonatomicString and setNonatomicString automatically

	a property access for obj.nonatomicString is = [obj getNonatomicString]