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For 2021 - online Python 3 training - see ((here)).

Our plans were to retire in summer 2020 and see the world, but Coronavirus has lead us into a lot of lockdown programming in Python 3 and PHP 7.
We can now offer tailored online training - small groups, real tutors - works really well for groups of 4 to 14 delegates. Anywhere in the world; course language English.

Please ask about private 'maintenance' training for Python 2, Tcl, Perl, PHP, Lua, etc.
Example of OO in Perl

Although Perl 5 doesn't use the words "class", "method" or "object" (or any of the other common OO words), it never the less has a very good OO model indeed - here's the source code of an example, together with the result of running the sample. I'll then give you a few clues!

use train;
use bus;
 
push (@ptl, new train("07:17",2,75));
push (@ptl, new train("06:40",3,60));
push (@ptl, new bus("07:12",2,40));
push (@ptl, new bus("08:10",1,61));
 
for $tranbit (@ptl) {
 print $tranbit;
 print " ",$tranbit->getstaff();
 print " ",$tranbit->getcapacity();
 print " ",$tranbit->getwhat();
 print "\n";
 }
 
__END__
 
The stuff below is comments as held in this
file. Split it out to separate files if you
want to run it!
 
############### train.pm
 
package train;
 
use pt;
@ISA = ("pt");
 
sub getstaff {
 return 1;
 }
 
sub getwhat {
 return ("Metal wheeler");
 }
 
1;
 
############### bus.pm
 
package bus;
 
use pt;
@ISA = ("pt");
 
sub getstaff {
 my ($self) = @_;
 return $$self{nv};
 }
 
sub getwhat {
 return ("Rubber wheeler");
 }
 
1;
 
####################### pt.pm
 
 
package pt;
 
sub new {
 my($class,$time,$nv,$vc)=@_;
 my %info;
 $info{time} = $time;
 $info{nv} = $nv;
 $info{vc} = $vc;
 bless \%info,$class;
 }
 
sub getcapacity {
 my ($self) = @_;
 return $$self{nv}*$$self{vc};
 }
 
1;
 
################## Runs as ...
 
 
j8pl grahamellis$ perl tharness
train=HASH(0x801c70) 1 150 Metal wheeler
train=HASH(0x815f60) 1 180 Metal wheeler
bus=HASH(0x815f9c) 2 80 Rubber wheeler
bus=HASH(0x815ff0) 1 61 Rubber wheeler
j8pl grahamellis$



Right. Now ...

A Perl package is a class
A Perl sub is used to define a method
The list @ISA defines inheritance
Perl's bless function defines the container for variables in the object
my defines a locally scoped variable
-> is used to invoke a method on an object
(written 2008-06-03)

 
Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
P218 - Perl - More Objects
  [227] Bellringing and Programming and Objects and Perl - (2005-02-25)
  [246] When to bless a Perl variable - (2005-03-15)
  [531] Packages in packages in Perl - (2005-12-16)
  [588] Changing @INC - where Perl loads its modules - (2006-02-02)
  [592] NOT Gone phishing - (2006-02-05)
  [656] Think about your design even if you don't use full UML - (2006-03-24)
  [831] Comparison of Object Oriented Philosophy - Python, Java, C++, Perl - (2006-08-13)
  [930] -> , >= and => in Perl - (2006-11-18)
  [1217] What are factory and singleton classes? - (2007-06-04)
  [1320] Perl for Larger Projects - Object Oriented Perl - (2007-08-25)
  [1435] Object Oriented Programming in Perl - Course - (2007-11-18)
  [1665] Factory method example - Perl - (2008-06-04)
  [1819] Calling base class constructors - (2008-10-03)
  [1949] Nuclear Physics comes to our web site - (2008-12-17)
  [2427] Operator overloading - redefining addition and other Perl tricks - (2009-09-27)
  [2651] Calculation within objects - early, last minute, or cached? - (2010-02-26)
  [2717] The Multiple Inheritance Conundrum, interfaces and mixins - (2010-04-11)
  [2811] Igloos melt in the summer, but houses do not - (2010-06-15)
  [2876] Different perl examples - some corners I rarely explore - (2010-07-18)
  [2972] Some more advanced Perl examples from a recent course - (2010-09-27)
  [3097] Making Perl class definitions more conventional and shorter - (2010-12-20)
  [3098] Learning Object Orientation in Perl through bananas and perhaps Moose - (2010-12-21)
  [3377] What do I mean when I add things in Perl? - (2011-08-02)
  [3581] Perl - calls to methods that use => - what do they mean? - (2012-01-16)
  [3941] Building an object based on another object in Perl - (2012-12-03)
  [4096] Perl design patterns example - (2013-05-20)
  [4098] Using object orientation for non-physical objects - (2013-05-22)
  [4356] Object factories in C++, Python, PHP and Perl - (2014-12-19)
  [4366] Changing what operators do on objects - a comparison across different programming languages - (2014-12-26)

P213 - Perl - Creating your own Classes
  [975] Answering ALL the delegate's Perl questions - (2006-12-09)
  [983] Blessing in Perl / Member variable in Ruby - (2006-12-14)
  [1864] Object Oriented Perl - First Steps - (2008-11-01)
  [1925] Introduction to Object Oriented Programming - (2008-12-06)
  [2169] When should I use OO techniques? - (2009-05-11)
  [2834] Teaching examples in Perl - third and final part - (2010-06-27)
  [2877] Further more advanced Perl examples - (2010-07-19)
  [2969] What does blessing a variable in Perl mean? - (2010-09-24)
  [3059] Object Orientation in an hour and other Perl Lectures - (2010-11-18)
  [3833] Learning to use existing classes in Perl - (2012-08-10)
  [4607] Classes and object - first steps in Perl 6 - (2016-01-02)


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Factory method example - Perl
Some other Articles
Talk on TransWilts train service to Green Party
Checking server performance for PHP generated pages
Slow boot and terminal start on Linux boxes
Example of OO in Perl
Python in an afternoon - a lecture for experienced programmers
Westonbirt Arboretum Postcode
Equality, sameness and identity - Python
Korn shell - some nuggets
String, Integer, Array, Associative Array - ksh variables
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This is a page archived from The Horse's Mouth at http://www.wellho.net/horse/ - the diary and writings of Graham Ellis. Every attempt was made to provide current information at the time the page was written, but things do move forward in our business - new software releases, price changes, new techniques. Please check back via our main site for current courses, prices, versions, etc - any mention of a price in "The Horse's Mouth" cannot be taken as an offer to supply at that price.

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