title: Private and protected methods in Objective-C
body: <p>What is the recommended way to define private and protected methods in Objective-C? One website suggested using categories in the implementation file for private methods, another suggested trailing underscores, or XX_ where XX is some project-specific code. What does Apple itself use?</p>
  
  <p>And what about protected methods? One solution I read was to use categories in separate files, for example CLASS_protected.h and CLASS_protected.m but this seems like it could get very bloated. What should I do?</p>