Subroutines in Perl

Subroutines in Perl - module P209

As your code grows in size, you'll want to divide it down into manageable chunks for ease of maintenance, and so that you can reuse logic at different points in the same application, or even from different applications. Perl's way of naming a block of code is a "subroutine".

This topic is presented on public courses Perl Programming, Perl bootcamp

Examples from our training material

bridges.pm	subroutines called up from example applications
courses.pl	Sample (test) program to try out a diary
cov2.pm	Coverage as a class. Allows multiple parallel coverage sets!
coverage.pm	Routines to combine integer ranges to provide overall coverage information
covertest	Sample application - coverage test given ranges of integers
ct2	Coverage test - application using coverage objects
diaryev.pm	Sample class for courses.pl demo
email.pm	email class of objects - a very simple class
globvar	demonstration that variables default to global
mailfilter.pm	package to encapsulate information - NOT really objects.
mailister2	including package name in package methods
maillister	using a module to retain information
mc	Email analysis via a package
mc2	using email objects
mf2.pm	package of subroutines for mailfilter2
ms2	calling subroutines in a different file
mysub	calling a subroutine in the same file
myvar	Use of my to reduce variable persistance and scope
subgetnum	Sample use of subroutines - returned parameters
subgnrange	Passing parameters in and out of subroutines
substamp	Sample use of subroutines
valread.pm	standard subroutines to include in several programs

Background information

Some modules are available for download as a sample of our material or under an Open Training Notes License for free download from http://www.training-notes.co.uk.

Topics covered in this module

What are subroutines and why?.
The limitations of "single block code".
First use of subroutines.
Structured programming.
Object oriented programming.
Calling a subroutine.
Passing values out of subroutines.
Passing values in to subroutines.
Writing your own subroutine.
Passing parameters in.
Returning values.
Writing subroutines in a separate file.
Scope.
Global Scope.
my variables.
A test program:.
packages.
Calling objects.
Writing a class - an introduction.

Complete learning

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