class

• blueprint for a user-defined data type
  • consists of instance variables + methods

object

• an instance of a class

concept of numbers (data type) and the actual number (object)

• every bank account has its own balance, name, number

  • these are all instance variables

• classes have things that we do

• we interact with bank account objects

  • these are are all different methods

• constructors are used to create an object of this type

• intialize instance variables

• the job of the constructor is to initialize the instance variables

• we have blueprints for NEW KINDS of data types

• we want to write code that manipulates bank accounts, so we need to make our own versions

• declarations alloct the appropriate amount of memory + provides context + provides scope for the variable

  • scope: where in a program a variable is accessible