14.15 Privacy

• Private fields and methods - elements that can only be accessed from within the class, not from the outside.
• We need to know two things to use private elements:
  1. private’s interface is just like public’s interface.
     • List of methods (functions) and fields (everything else).
  2. You use private$ instead of self$
     • You cannot access private fields or methods outside of the class.
• Why might you want to keep your methods and fields private?
  • You’ll want to be clear what is ok for others to access, especially if you have a complex system of classes.
  • It’s easier to refactor private fields and methods, as you know others are not relying on it.