can you tell me simple what they are and how they work?


 "A computer lets you make more mistakes faster than any other human invention in history....
with the possible exception of handguns and tequila" -Mitch Ratcliffe-

Patterns are ideas about the design of programs that have been tried and found to work well for a certain task. Vaguely akin to the idea equivalent of an object these ideas can then be catalogued and reused. Check:

http://en.wikipedia.org/wiki/Design_pattern_(computer_science)

HTH
CHarlie

--
Don't Stand on your head - you'll get footprints in your hair
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