Objects and Classes

Objects and Classes

1. Object-oriented programming (OOP)

2. Classes

   • The blueprint for creating objects; the template - determines what kind of objects you get
     • Objects aka Instance
       • Have two features that can be performed: attributes and actions. They are optional. (both use camel naming convention)
         • Attributes = Fields: variables
         • Actions = Methods: define actions that a class's objects can do
           • has a declaration part (aka signature of the method. and a body)
             • part has a return value, the method name, and a list of arguments
               • return type can be a primitive, an object, or void(returns nothing)
             • body has code that perform the action
       • an object can contain other objects, that is if the class of the former contains variables that reference to the latter.
   • fundamental building blocks of a Java program
   • Must consider: class name (uses pascal naming convention), fields and methods
   • Every class must have at least one constructor. Otherwise, no objects could be created out of the class and the class would be useless
     • Constructor looks like a method but doesn't have a return value or void