Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online.Cyclomatic complexity (or conditional complexity) is a software metric (measurement). It was developed by Thomas J. McCabe Sr. in 1976 and is used to measure the complexity of a program. It directly measures the number of linearly independent paths through a program's source code. The concept, although not the method, is somewhat similar to that of general text complexity measured by the Flesch- Kincaid Readability Test.Cyclomatic complexity is computed using the control flow graph of the program: the nodes of the graph correspond to indivisible groups of commands of a program, and a directed edge connects two nodes if the second command might be executed immediately after the first command. Cyclomatic complexity may also be applied to individual functions, modules, methods or classes within a program.One testing strategy, called Basis Path Testing by McCabe who first proposed it, is to test each linearly independent path through the program; in this case, the number of test cases will equal the cyclomatic complexity of the program.