There are certain programming tasks that sound simple but end up fascinating ... they sound straightforward (and probably are), but it turns out there are lots of ways of doing them and you could spend a lot of time working out which was is best. One of those is converting three letter abbreviations for months into numbers. Sounds easy, doesn't it ... well - it is, but which way would you go?

a) A series of "if" and "elseif" statements

b) A string of 36 letters JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC and see where your month name appears in that

c) A switch statement with 12 choices (Obviously not available on languages that don't have a switch)

d) An array (Tcl), Hash (Perl), Table (Lua), Associative array (PHP) or dictionary (Python) where the keys are the names of the month and the values are the month numbers

e) A list (Tcl, Perl), Tuple (Python) , indexed array(PHP) indexed table (Lua) through which you search for the month string and return the index you're on when you find it.

I've put up a sample - in Lua - showing (a), (b) and (d) - it's [here] and comes from discussions on this week's course. There's no switch in Lua - and indeed the Lua user's Wiki sends you back to option (a) - see [here]. And option (e) is so inefficient and horrid that I'm not going to lower myself to write that code in Lua (note, though that the in operator in Python may make it acceptable there!
(written 2010-09-10)

 Q110 - Object Orientation and General technical topics - Programming Algorithms
  [3662] Finding all the unique lines in a file, using Python or Perl - (2012-03-20)
  [3620] Finding the total, average, minimum and maximum in a program - (2012-02-22)
  [3451] Why would you want to use a Perl hash? - (2011-09-20)
  [3102] AND and OR operators - what is the difference between logical and bitwise varieties? - (2010-12-24)
  [3093] How many toilet rolls - hotel inventory and useage - (2010-12-18)
  [3072] Finding elements common to many lists / arrays - (2010-11-26)
  [3042] Least Common Ancestor - what is it, and a Least Common Ancestor algorithm implemented in Perl - (2010-11-11)
  [2993] Arrays v Lists - what is the difference, why use one or the other - (2010-10-10)
  [2894] Sorting people by their names - (2010-07-29)
  [2617] Comparing floating point numbers - a word of caution and a solution - (2010-02-01)
  [2586] And and Or illustrated by locks - (2010-01-17)
  [2509] A life lesson from the accuracy of numbers in Excel and Lua - (2009-11-21)
  [2259] Grouping rows for a summary report - MySQL and PHP - (2009-06-27)
  [2189] Matching disparate referencing systems (MediaWiki, PHP, also Tcl) - (2009-05-19)
  [1949] Nuclear Physics comes to our web site - (2008-12-17)
  [1840] Validating Credit Card Numbers - (2008-10-14)
  [1391] Ordnance Survey Grid Reference to Latitude / Longitude - (2007-10-14)
  [1187] Updating a page strictly every minute (PHP, Perl) - (2007-05-14)
  [1157] Speed Networking - a great evening and how we arranged it - (2007-04-21)
  [642] How similar are two words - (2006-03-11)
  [227] Bellringing and Programming and Objects and Perl - (2005-02-25)
  [202] Searching for numbers - (2005-02-04)

U112 - Lua - Other Standard Library features.
  [1847] Lua - IAQ (Infrequently Answered Questions) - (2008-10-18)

Back to Camilla, Duchess of Cornwall, turns first sod in Melksham Link Canal

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Forward to Concluding the interview process

Melksham Railway Station - new information point
Railway meetings, trips and meetups this autumn
Turning an exercise into the real thing with extreme programming
Concluding the interview process
Lots of way of converting 3 letter month abbreviations to numbers
Camilla, Duchess of Cornwall, turns first sod in Melksham Link Canal
Lua - variable function arguments and select
Melksham shamefully makes the national headlines
Teaching Lua to a Perl advocate
Level playing fields, job vacancies, lemons and peaches