Introduction to Objects

In traditional (functional) programming, variables and functions are distinct. With object-oriented programming, variables and functions are grouped together in objects. An object contains data and that data has behavior (functions) associated with it that specify in what way the data can change.

Why use objects?

Using objects reduces the complexity of a program by seperating it into smaller components of data and behavior. It also offers the potential of code reuse by using a existing data and behavior grouping (ojbect) in different contexts without having to reimplement the code for it. Object-oriented programming is a complicted subject. For more information see the Perl Object-Oriented Tutorial.

• Class and object variables
• Class and object methods
• Overiding of methods
• Cconstructor and destructor methods
• Dynamic class creation
• Single and multiple inheritance
• Single-rooted hierarchy (common base class)

Indirectly supported are:

• Private variables
• Inheritance of data variables
• Automated delegation of methods

Not support in Perl are:

• compile-time checking
• private functions
• checking of function signatures