@interface, @implementation, @protocal in Objective-c

Following

• void print ();

• };
• Class ac{
• };

• At this time, the AI and AC are independent, AC does not have to build a relationship with the AI to compile the error, the following modifications to the AC, the AI to establish a relationship with AC, AC must implement the method declared in the AI to compile.
  
  

  [HTML] view Plaincopyprint?
  1. Class AC Implement ai{
  2. void print () {
  3. System.out.println (' Hello world ');
  4. }
  5. };
  
  Now, let's see <foundation/foundation.h>
• @protocol A
• @end
• <strong style="Color:white;background-color: #880000"> @interface</Strong > A:nsobject<A>
• -(void) test: (ID<A>) obj;
• @end
• 
  Notice here-(void) test: (id<a>) obj; This indicates that the test method accepts an arbitrary type of object as a parameter, but the parameter object must implement interface A, similar to the one in Java
  
  void Test (List<a> obj).

@interface, @implementation, @protocal in Objective-c