Most Efficient Way to Test Object Type

Question

I have values stored as strings in a DataTable where each value could really represent an int, double, or string (they were all converted to strings during an import process from an external data source). I need to test and see what type each value really is.

What is more efficient for the application (or is there no practical difference)?

1. Try to convert to int (and then double). If conversion works, the return true. If an exception is thrown, return false.
2. Regular expressions designed to match the pattern of an int or double
3. Some other method?

Answer 1

Would use double.TryParse, it has performance benefits.

Answer 2

I would say, don't worry so much about such micro performance. It is much better to just get something to work, and then make it as clear and concise and easy to read as possible. The worst thing you can do is sacrifice readability for an insignificant amount of performance.

In the end, the best way to deal with performance issues is to save them for when you have data that indicates there is an actual performance problem... otherwise you will spend a lot of time micro-optimizing and actually cause higher maintenance costs for later on.

If you find this parsing situation is really the bottleneck in your application, THEN is the time to try and figure out what the fastest way to solve the problem is. I think Jeff (and many others) have blogged about this sort of thing a lot.