Write a bulletproof date validation routine.

[Neo]

Looks interesting. Give me some time to run a test on it (more than 20 minutes) like I did with Meg's solution. I'll get back to you.

So, how's it getting along? I hope it works (although it might be a bit slower than Meg's solution, due to the fact I implemented more checks) I'm glad the solution looked interesting

Orthoganality is like the concept of independence in statistics, as well as a concept from gemotry I think . Object orientated libraries are a prime example of this - plug it in, read the API documentation, code your use of it. Performance gains using this method are huge

Exactly I'm not experienced in statistics, but in geometry e.g. most axis systems are orthogonal.

Code:

y
^
|
|
|
|
+--
       x

The common Carthesian coordinate system is orthogonal as well. When you have coordinate in this coordinate system, like (1,1), changing the x-value of this coordinate (i.e. sliding it left/right), doesn't affect the y-value of the coordinate. And vice versa changing the y-coordinate doesn't affect the x-coordinate. Carthesian is orthogonal.

Now you'd say, aren't all axis systems orthogonal? No, like this para-carthesian:

Code:

y
      _
     /|
    /
   /
  /
+--
       x

In this coordinate system, the y-coordinate is the intersect y-value of the perpendicular line through the y-axis. In this case, if you change x, y changes as well, and vice versa.

Of course, OOP was invented to increase orthogonality