data types

• every value is either an object reference or a primitive data type

  

• unlike primitives, classes are user-defined data types

  • we can create our own levels of complexity

what is a class

• a blueprint that defines:
  • what an object is
  • what an object does
• what data an object stores and what functionalities that object will have
• instance variables
• instance methods

what is an object

• an object is an instance of a class
• it creates its own copies of the instance variables defined in the class
• objects of the same class share behaviors
• has the functionalities defined by the instance methods

ex:

• these objects all share behaviors bc they are all objects of the same class

• mutator methods make some change
  • they are often "void"