<h3>Why should you care?</h3>
Because it will make you write maintainable code less prone to error.
<h3>What is cyclomatic complexity?</h3>
Cyclomatic complexity is a code metric. It is a number that corresponds to the total amount of execution paths through your code. This number is per method and is calculated like so:
- start with 1 as count
- for each branching keyword or operator add one to count
Keywords include if, for, while, case (not switch, count each keyword that represents a possible execution branch).
Operators include the ternary operator, and the null-coalescing/elvis operator if your language supports it. The below examples demonstrate a few languages and a branching operator (each example add one to count):
<h3>How can it help you?</h3>
I maintain a cyclomatic complecity count in my mind as I author code, and it makes it harder for me to author stupid code.
Every time I want to add a new execution branch I first explore other ways to accommodate the requirement (such as extending or appending to an existing if statement, or take care of the requirement in another location entirely).