Seven (or eight) reasons to use test driven development

• It helps you to break down problems into manageable segments before a line of code has been written.
• If you can write a test for it you also have some idea of the results that you're expecting.
• If you have some idea of the results you understand the specification of the software that you're writing.
• Once you're satisfied that a test has been passed you can move onto the next problem, i.e. writing the next test case.
• You both understand and are familiar with all the important specifications and therefore are these not likely to change.
• Test cases is in one way equal to the most important and shortest comment blocks (if they are really necessary).
• You don't like to spend lots of time debugging.
• You have the opinion that smarter and normally (in comparison to others that have more or less the same result) shorter source code means that you're more productive.