Magic numbers, especially if they appear in more than one place. They really want to be named constants, but they also have to be named in a way that is not dependent on the actual value. For example, worldPopulation = 6,973,738,433.
Thursday, September 13, 2012
The five (5) principles
... and here they are:
Single responsibility!
Open-closed! (but watch out for: single responsibility)
Liskov substitution!
Interface segregation! (see also: single responsibility)