1. Home
  2. Programming
  3. Perl objects, references and modules

Chapter 3. Introduction to References

A Perl scalar variable holds a single value. An array holds an ordered list of one or more scalars. A hash holds a collection of scalars as values, keyed by other scalars.

Although a scalar can be an arbitrary string, which allows complex data to be encoded into an array or hash, none of the three data types are well-suited to complex data interrelationships. This is a job for the reference. Let's look at the importance of references by starting with an example.



    		Chapter 1. Introduction
    		Chapter 2. Building Larger Programs
    		Chapter 3. Introduction to References
    		3.1 Performing the Same Task on Many Arrays
    		3.2 Taking a Reference to an Array
    		3.3 Dereferencing the Array Reference
    		3.4 Dropping Those Braces
    		3.5 Modifying the Array
    		3.6 Nested Data Structures
    		3.7 Simplifying Nested Element References with Arrows
    		3.8 References to Hashes
    		3.9 Exercises
    		Chapter 4. References and Scoping
    		Chapter 5. Manipulating Complex Data Structures
    		Chapter 6. Subroutine References
    		Chapter 7. Practical Reference Tricks
    		Chapter 8. Introduction to Objects
    		Chapter 9. Objects with Data
    		Chapter 10. Object Destruction
    		Chapter 11. Some Advanced Object Topics
    		Chapter 12. Using Modules
    		Chapter 13. Writing a Distribution
    		Chapter 14. Essential Testing
    		Chapter 15. Contributing to CPAN
    		Appendix A. Answers to Exercises