Home Accessibility Courses Twitter The Mouth Facebook Resources Site Map About Us Contact
 
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.
Do not copy and paste code - there are much better ways

If you find yourself using copy and paste to duplicate a piece of code, take a step back and think again. You're doubling your maintenance work, with two separate sets of code to look after and keep in step from that day forwards.

Are you going to give me the "but I have to change one copy a bit" excuse? Please don't ... in identifying which bits need changing, you have identified the parameters for a named block of code ... which will be known as a sub / subroutine / function / macro / method / procedure / command depending on which language you're writing in.

There's an example in [this bit of code] which I wrote yesterday in Perl, looking for Christmas topics within place names (Well - as someone else said ... "the programs on the TV weren't worth watching") ...

And if you want to try the code out, there's a web based derivative [here]. Enjoy!

(written 2009-12-26, updated 2010-01-06)

 
Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
Q101 - Object Orientation and General technical topics - Programming Principles
  [2001] I have not programmed before, and need to learn - (2009-01-19)
  [2022] Pre and post increment - the ++ operator - (2009-02-03)
  [2228] Where do I start when writing a program? - (2009-06-11)
  [2310] Learning to write high quality code in Lua - (2009-07-30)
  [2327] Planning! - (2009-08-08)
  [2415] Variable names like i and j - why? - (2009-09-22)
  [2510] The music of the stock market - (2009-11-22)
  [2586] And and Or illustrated by locks - (2010-01-17)
  [2737] Improving your function calls (APIs) - General and PHP - (2010-04-24)
  [2769] Easy - but for whom? - (2010-05-18)
  [2878] Program for reliability and efficiency - do not duplicate, but rather share and re-use - (2010-07-19)
  [2915] Looking up a value by key - associative arrays / Hashes / Dictionaries - (2010-08-11)
  [2964] An introduction to file handling in programs - buffering, standard in and out, and file handles - (2010-09-21)
  [3026] Coding efficiency - do not repeat yourself! - (2010-11-02)
  [3456] Stepping stones - early coding, and writing re-usable code quickly - (2011-09-24)
  [3542] What order are operations performed in, in a Perl expression? - (2011-12-07)
  [3548] Dark mornings, dog update, and Python and Lua courses before Christmas - (2011-12-10)
  [3551] Some terms used in programming (Biased towards Python) - (2011-12-12)
  [3673] Object oriented or structured - a comparison in Python. Also writing clean regular expressions - (2012-03-26)
  [3878] From Structured to Object Oriented Programming. - (2012-10-02)
  [3928] Storing your intermediate data - what format should you you choose? - (2012-11-20)
  [3954] Lesson 1 in programing - write clean, reuseable and maintainable tidy code - (2012-12-16)
  [4003] Web and console - same principle, same code - Ruby example - (2013-02-14)
  [4061] Seamless, integrated IT - we have a long way to go! - (2013-04-11)
  [4090] Test Driven Development in Python - Customer Comes First - (2013-05-16)
  [4118] We not only teach PHP and Python - we teach good PHP and Python Practice! - (2013-06-18)
  [4153] Rooms available tonight - how to code an algorithm from first principles - (2013-08-19)
  [4206] Writing the perfect program in Tcl? - (2013-11-13)
  [4325] Learning to program - what are algorithms and design patterns? - (2014-11-22)
  [4611] Hungarian, Camel, Snake and Kebab - variable naming conventions - (2016-01-03)
  [4632] Remember to ask the question before you listen for the answer - (2016-01-26)
  [4645] What are callbacks? Why use them? An example in Python - (2016-02-11)

P209 - Subroutines in Perl
  [96] Variable Scope - (2004-10-22)
  [308] Call by name v call by value - (2005-05-11)
  [357] Where do Perl modules load from - (2005-06-24)
  [531] Packages in packages in Perl - (2005-12-16)
  [588] Changing @INC - where Perl loads its modules - (2006-02-02)
  [775] Do not duplicate your code - (2006-06-23)
  [969] Perl - $_ and @_ - (2006-12-07)
  [1163] A better alternative to cutting and pasting code - (2007-04-26)
  [1202] Returning multiple values from a function (Perl, PHP, Python) - (2007-05-24)
  [1782] Calling procs in Tcl and how it compares to Perl - (2008-09-02)
  [1784] Global - Tcl, PHP, Python - (2008-09-03)
  [1826] Perl - Subs, Chop v Chomp, => v , - (2008-10-08)
  [1850] Daisy the Cow and a Pint of Ginger Beer - (2008-10-21)
  [1860] Seven new intermediate Perl examples - (2008-10-30)
  [1921] Romeo and Julie - (2008-12-04)
  [2069] Efficient calls to subs in Perl - avoid duplication, gain speed - (2009-03-07)
  [2833] Fresh Perl Teaching Examples - part 2 of 3 - (2010-06-27)
  [2929] Passing a variable number of parameters in to a function / method - (2010-08-20)
  [3066] Separating groups of variables into namespaces - (2010-11-24)
  [3574] Perl functions such as chop change their input parameters - (2012-01-10)
  [3833] Learning to use existing classes in Perl - (2012-08-10)

P204 - Perl - Conditionals and Loops
  [353] Wimbledon Neck - (2005-06-20)
  [930] -> , >= and => in Perl - (2006-11-18)
  [1191] Smart English Output - via PHP and Perl ? : operator - (2007-05-18)
  [1468] Lexical v Arithemetic testing, Bash and Perl - (2007-12-11)
  [1477] Decisions - small ones, or big ones? - (2007-12-18)
  [1607] Learning to program in Perl - (2008-04-11)
  [1696] Saying NOT in Perl, PHP, Python, Lua ... - (2008-07-04)
  [1727] Equality and looks like tests - Perl - (2008-07-29)
  [2351] Ternary operators alternatives - Perl and Lua lazy operators - (2009-08-12)
  [2711] For loop - checked once, or evety time? Ruby v Perl comparison and contrast - (2010-04-07)
  [2832] Are you learning Perl? Some more examples for you! - (2010-06-27)
  [3004] Increment operators for counting - Perl, PHP, C and others - (2010-10-18)
  [3397] Does a for loop evaluate its end condition once, or on every iteration? - (2011-08-18)
  [3895] Flowchart to program - learning to program with Well House - (2012-10-14)
  [4031] Showing what programming errors look like - web site pitfall - (2013-03-06)
  [4322] Learning to Program - the conditional statement (if) - (2014-11-21)
  [4323] Learning to program - Loop statements such as while - (2014-11-22)


Back to
Christmas Day ...
Previous and next
or
Horse's mouth home
Forward to
Perl and the Common Gateway Interface - out of fashion but still very useful?
Some other Articles
Adding retrospective ALT attributes to IMG
On a short walk from home
Web site traffic - real users, or just noise?
Perl and the Common Gateway Interface - out of fashion but still very useful?
Do not copy and paste code - there are much better ways
Christmas Day ...
Ten years ago, we moved to Melksham Spa
The great thing about snow ....
How well do you know Melksham - a quiz for Christmas
Scraping content for your own page via PHP
4759 posts, page by page
Link to page ... 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96 at 50 posts per page


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.

Link to Ezine home page (for reading).
Link to Blogging home page (to add comments).

You can Add a comment or ranking to this page

© WELL HOUSE CONSULTANTS LTD., 2021: 48 Spa Road • Melksham, Wiltshire • United Kingdom • SN12 7NY
PH: 01144 1225 708225 • EMAIL: info@wellho.net • WEB: http://www.wellho.net • SKYPE: wellho

PAGE: http://www.wellho.net/mouth/2550_Do- ... -ways.html • PAGE BUILT: Sun Oct 11 16:07:41 2020 • BUILD SYSTEM: JelliaJamb