Adapted with permission from Arnold Rosenbloom, University of Toronto
*added by MisterV
Object Oriented Programming Language:
A programming language which allows the modelling of object interaction
- Java is an OO programming language.
- Typically an OO programming language supports:
- Encapsulation (via the notion of class)
- Inheritence: method for extending existing classes by adding methods and fields
- Polymorphism: Behaviour varies depending on the actual type of an object
- OO Programming Languages encourage code reuse, capturing of concepts
Programming the OO way...
- Problem solve: Understand a given problem (there is a LOT to this!!) Determine if a solution takes the form of a computer program (and if so)...
- Create Conceptual Solution: Describe the system to be modelled. That is, give an english description of the system
- Concepts mapped to OO Paradigm:
- Think OO: Analyze the problem/solution, view it as a collection of interacting objects, then identify the
- classes/objects: These are the concepts that need to be captured. Sometimes noun or noun phrases in the above description.
- methods (RESPONDS-TO): for each class. These are the things that the class can do. Verbs usually identify these in the problem description.
- attributes (HAS-A): for each class. These are things that each instance has, they define the state of the instance.
- inheritence (IS-A): classes that this class extends
- Think Algorithmically: Write algorithms for each of the methods
- Java: Translate the above to something the computer can understand (Java)
- a=b calculated by computing the VALUE of the right side and placing it in the left
- Methods in Java pass parameters by VALUE
- Java occasionally garbage collects instances that have no references to them.