Perl 5 Object Oriented Programming

Prerequisites:

- Existing Perl 5 developers who wish to write and use object orientation. Support staff with Perl 5 experience who intend to support Perl classes and code that uses Perl objects.

- Delegates must have recent day-to-day experience of Perl. No previous OO experience is necessary.

Course Description:

Perl 5 is a highly successfully high level programming language. This short course discusses Perl's object orientation features.

To the uninitiated Perl does not at first appear to have many OO features. However most modules are written with an OO interface these days, and today's programmers expect languages to be capable of OO. Perl has these features, although the techniques to use them may be different from other popular languages. This course not only describes the basic syntax and implementation details, it discusses the techniques required to use them effectively.

Practical exercises are used to consolidate the information learned during the lecture sessions and demonstrations. These will demonstrate many of the differences between alternative implementations.

Course Objectives

On completing this course, you will be able to:

- Explain the basic concepts and terminology of object-oriented programming
- Use common objects and references types
- Create, initialise, and destroy objects in a Perl application
- Store class structures and objects for later reuse
- Derive new Perl classes from existing classes
- Create self-contained classes in a Perl application
- Understand different forms of Perl Encapsulation, and choose between them
- Use advanced features of Perl 5 object orientation

This course includes the following modules:

Review of References

• What are references
• Creating references
• Using references
• Dereferencing array and hash references
• Examining references

Review of Subroutines and Modules

• Review of subroutines
• Parameter passing
• References to subroutines
• Review of Modules
• Module loading
• Namespaces
• Multiple packages

Overview of Perl OO

• OO concepts and terms
• Basic object usage
• Implementing objects
• Accessing object fields
• Constructors
• Implementing object methods
• Method call syntax

Constructors and Destructors

• Object constructors
• Object destructors
• Reference counting
• Object data types
• Named and virtual constructors
• Exemplar registry
• Singletons

Inheritance and Overloading

• Method inheritance
• Constructor inheritance
• Multiple inheritance
• SUPER
• UNIVERSAL
• Operator overloading

Encapsulation

• Defining an object
• The fields pragma and strong typing
• Constructing inside-out objects
• Inside-out destructors
• Accessors
• Inside-out Accessors