When writing code, it is important to ensure that each statement serves a purpose and
contributes to the overall functionality of the program. When they have no side effects or do not change the control flow, they can either indicate a programming error or be redundant:

1. The code does not behave as intended: The statements are
   expected to have an effect but they do not. This can be
   caused by mistyping, copy-and-paste errors, etc. 

2. The statements are residual after a refactoring.