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For 2023 - we are now fully retired from IT training.
We have made many, many friends over 25 years of teaching about Python, Tcl, Perl, PHP, Lua, Java, C and C++ - and MySQL, Linux and Solaris/SunOS too. Our training notes are now very much out of date, but due to upward compatability most of our examples remain operational and even relevant ad you are welcome to make us if them "as seen" and at your own risk.

Lisa and I (Graham) now live in what was our training centre in Melksham - happy to meet with former delegates here - but do check ahead before coming round. We are far from inactive - rather, enjoying the times that we are retired but still healthy enough in mind and body to be active!

I am also active in many other area and still look after a lot of web sites - you can find an index ((here))
An example of Java Inheritance from scratch

One of the most important topics for newcomers to OO (Object oriented) programming to learn is how to design their classes and make best use of inheritance, and I find myself writing new examples from first principles during our courses. That way, the delegates learn how to actually do the job - they're NOT just presented with a "here is one I wrote earlier" and left to struggle!

In order to let the delegates then refer to the code I wrote, I've put it up on our wiki ... the web formatting isn't very tidy, but it's a great "all in one place" reference for them when they come to do their own practical.

The first example is at http://www.wellho.net/share/javainherit.html. It's a base class called "Animal" with two subclasses called "Farm" and "Pet" with the whole thing being tested by "Anitest". The beauty of using inheritance in this way is that you can put the common code in "Animal" and then just the farm-specific or pet-specific stuff into the Farm and Pet classes - saves code duplication.

That first example isn't perfect, though. We want to extend it as follows:
a) To have an array of animals that we can loop through
b) To use a utility function to handle multiple similar methods
c) To provide static methods than work on the whole
d) To set up Animal such that we can force all extended classes to have specific enhancements ("abstract")
e) To provide functions to compare two or more objects in a way we define.
These extras are in my second example at http://www.wellho.net/share/javainherit2.html.
(written 2007-08-08, updated 2014-11-05)

Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
J706 - Java - Objects and Classes
  [96] Variable Scope - (2004-10-22)
  [477] Class, static and unbound variables - (2005-10-25)
  [1163] A better alternative to cutting and pasting code - (2007-04-26)
  [1500] First Class Java. First step and moving forward. - (2008-01-10)
  [1906] Long, Longer, Longest in Java - (2008-11-25)
  [1925] Introduction to Object Oriented Programming - (2008-12-06)
  [2169] When should I use OO techniques? - (2009-05-11)
  [2422] Looking inside Java classes - javap and javadoc - (2009-09-25)
  [2616] Defining a static method - Java, Python and Ruby - (2010-02-01)
  [2651] Calculation within objects - early, last minute, or cached? - (2010-02-26)
  [4413] Binomial Coefficient (Pascal Triangle) objects in Java - (2015-02-03)
  [4422] Objects - from physical to virtual or abstract - Java - (2015-02-10)

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DHCP automatic IP address v Static IP
Day trip to Weymouth
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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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