What Is Cyclomatic Complexity: A Complete Guide

A cyclomatic complexity is a software metric used to measure the complexity of a program's control flow, helping teams identify the minimum number of test cases needed to cover all paths through a program's source code. Cyclomatic complexity measures the complexity of a program by calculating the number of independent paths in the code. A higher score indicates more execution paths and complexity, while a low score indicates low complexity with fewer paths and simple code. Programs with high complexity are more open to errors and difficult to test and maintain, whereas programs with lower complexity are easy to understand, test, and modify. Cyclomatic complexity helps teams identify areas of the code that need more testing or redesign to make the codebase easier to manage. The formula to calculate cyclomatic complexity is V(G) = E – N + 2P, where E represents the number of edges or control paths in the program's Control Flow Diagram (CFG), N represents the number of decision points in the code, and P represents the number of connected components. By using this metric, teams can ensure thorough testing, improve code quality, and make the codebase easier to maintain and manage.