What Is Cyclomatic Complexity? Measuring Code Quality

Classifiers are built using the thirteen software metrics as independent variables and the module-class as the dependent variable, i.e., fp or nfp. Test-driven development is one way to bring in unit tests for the purposes of code coverage. To show the value that this work has to the larger organization, it may be necessary to set aside specific time during the work week to have them gather and be trained how to do TDD. Without actually setting aside time to introduce this new concept, the old saying of you get what you pay for is very true and results will be spotty at best.

Implementing any of those constructs introduces a new path through the code. The nodes are internally connected to each other when the next instruction is related to previous instruction. LinearB is a tool that can help you identify such risky areas. With its dashboard, you can correlate Jira analytics with Git statistics in a way that gives you a unique view of your team’s performance. Each week we share stories and advice from engineering and product leaders striving to be better for their teams.

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Code without unit tests is much more difficult to refactor with confidence, and when it does get modified the risk of introducing a new bug is high. Paths in complexity determine whether a program is complex, or whether there is a need to reduce complexity. The higher no. of complexity means the code is more complex.

In this case, the fix was simple — the coroutine has a bunch of tasks to do, so I break those tasks up into smaller coroutines, and replace the main method with calls to subroutines. The overall code didn’t change, and neither did the total complexity of the class itself, but now the main function isn’t a 400 line monstrosity. The fundamental group counts how many loops there are through the graph, up to homotopy, and hence aligns with what we would intuitively expect. Cyclometric Complexity is basically a software metric that is used to determine the complexity of a program. Mathematically, for a structured program, the directed graph inside the control flow is the edge joining two basic blocks of the program as control may pass from first to second. If condition then cyclomatic complexity will be 2 because there will be two paths one for true and the other for false.

Software Reliability

This is a little more managable, conceptually, I think – it’s easier to visualize or conceptualize the paths through a method than paths through a large application. Cyclomatic complexity can be calculated manually if the program is small. Automated tools need to be used if the program is very complex as this involves more flow graphs.

You can have methods with low cyclomatic complexity that are hard to reason about. We now have yet another branching that verifies the length of the person’s name. This makes the cyclomatic complexity of the function reach 3.

Steps to Calculate Cyclomatic Complexity with McCabe’s Formula

Cyclomatic complexity uses the graphical representation to calculate the complexity of the source program. The graph uses the linear independent path which represents the individual solution for the execution of source code. It is widely used for testing different software and finding defects in the source program. In fact it’s a measure of code complexity used in software development to point out more complex parts of code . You can calculate it using the E-N+2P formula, but I would suggest you have this calculated automatically by a plugin. I have heard of a rule of thumb that you should strive to keep the CC below 5 to maintain good readability and maintainability of your code.

• Be careful using cyclomatic complexity as a go-to metric for the project’s health.
• ]) is used to measure the complexity of a program by taking into account the number of linearly independent paths of a program.
• Without actually setting aside time to introduce this new concept, the old saying of you get what you pay for is very true and results will be spotty at best.
• Each casein the switch statement adds complexity, as it can lead to different outputs with differing inputs.
• The ownership of the code base was with the central team located in Country A, and she was a part of the offshore development team located in Country B.
• The places in your code with the biggest indents should have the highest CC.

Complexity is determine by branching (if statements, etc.) Complexity also might take in to account nesting of loops, etc. and other factors depending on the algorithum used. Visual Studio and other IDEs will calculate aggregate complexities of entire classes and namespaces, which can be useful for tracking down your most complex classes. You can sort by highest complexity and drill down into individual functions. Another application of cyclomatic complexity is in determining the number of test cases that are necessary to achieve thorough test coverage of a particular module.

A Dead Simple Cyclomatic Complexity Example

Connect and share knowledge within a single location that is structured and easy to search. For example, consider a program that consists of two https://www.globalcloudteam.com/ sequential if-then-else statements. Is an upper bound for the number of test cases that are necessary to achieve a complete branch coverage.

The recursive call is considered as one functional call otherwise it will create a loop situation that will create a problem to calculate the Cyclomatic complexity for source program. I’ll use a single function as an example, progressively increasing its complexity as we go. The examples will be in C# for the simple reason that it’s my go-to language. They should be easy to understand regardless of your language preferences. Since it has a single statement, it’s easy to see its cyclomatic complexity is 1.

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Instead of using a switch case to go over many possibilities and decide which one the code will execute, you can leverage the strategy pattern. https://www.globalcloudteam.com/glossary/cyclomatic-complexity/ Sure, at some point in the code, you’ll still need a switch case. After all, someone has to decide which actual implementation to use.

With a software language that has exception handling, it may be a large amount of work to produce a particular exception dealing with a network failure. A measure of reasonableness must be applied to the coverage metric. It is not necessary for management to produce an edict that all code must be 100% covered at all times, and yet at the same time this is the goal. The nature of the change approval process also discouraged refactoring. For instance, refactoring the class with lines would require breaking it up into several smaller cohesive classes. Since the approval for all these newly-created classes would require a long time, the team in Country B was not keen to refactor such large and complex classes.

Training for a Team

That’s oversimplifying it a big, but I think it gets the idea across. Cyclomatic Complexity is software metric useful for structured or White Box Testing. If the decision points are more, then complexity of the program is more. If program has high complexity number, then probability of error is high with increased time for maintenance and trouble shoot. For example, this code has a cyclomatic complexity of one, since there aren’t any branches, and it just calls WriteLine over and over.