You use:
-
public
scope to make that property/method available from anywhere, other classes and instances of the object. -
private
scope when you want your property/method to be visible in its own class only. -
protected
scope when you want to make your property/method visible in all classes that extend current class including the parent class.
If you don’t use any visibility modifier, the property / method will be public.
More: (For comprehensive information)
- PHP Manual – Visibility