Why Every Developer Should be a Good Tester

I have seen repeatedly, a developer a.k.a. programmer a.k.a. coder assumes that testing is not a part of his day-to-day job. His job is just write code and passes it to the testing team and the testing team will find all bugs and problems in the code.

http://www.c-sharpcorner.com/Blogs/5266/why-every-developer-should-be-a-good-tester.aspx