[christopherslee]

Software is all about tradeoffs, and there are so many ways a single problem could be solved. What works for me is to show them an alternative way that the code could be written.

Then you can have a practical discussion about the differences and what the differences are. Maybe their code is complex because they are considering more scenarios.

Sometimes, (not always), complex code is difficult to test. When I hear "the test is hard to write", it's a small to me that the code might be too complex.

[beyti]

These are the ones I really agree on. 1. If you can show an easy way, show it to him and hope for the best for him to next time he'll pay attention to use an easy to understand code if possible. 2. If your company goes for testing, show his/her code is hard to test.

Other than these aims in particular, you'll probably be ignored.