Unfortunately, software bugs are an inevitable part of the software development process. No code is perfectly crafted on the first go (although if you’ve ever managed such an incredible feat, let us know because, oof, that’s impressive, and we may need to buy you a beer to celebrate). 

We’ve already talked a little bit about what software bugs are and why (or when) you should pay for them, but it might also be helpful to share some insight on what kinds of software bugs exist. By identifying these various types of software bugs, developers and testers (like you!) can better deal with, manage, and squash them out for good. Sorry, Disney. 

Read on to learn more about eight of the most common types of software bugs or defects encountered in software testing and how to manage them.

1. Performance Bugs

Performance bugs are mainly related to the stability, speed, or response time of software resources and directly influence the users’ perception of the product. Dealing with performance bugs is especially tricky. In fact, according to research, fixing performance bugs is generally more difficult than fixing non-performance bugs, even though the two are equally prone to cause errors.

Basically, performance bugs usually don’t generate incorrect results or crash the program during testing. Therefore, they, unfortunately, can’t be detected by a simple check of the software output. 

How To Manage Them

Performance bug identification starts with great performance monitoring and detection software. Most modern cloud and hosting environments provide some level of analytics for monitoring your software performance. You can write alerts to detect when response times reach their bare minimum levels of acceptability to identify when your system is slowly beginning to degrade. 

For areas of your system that have strict performance requirements, you can write load tests to ensure that your system operates as you expect. With these tests in place, you can be sure that any new additions to your platform won’t inadvertently impact the performance of your system.

2. Functional Bugs

Functional bugs affect the functionality of a piece of software.

I know!!! Crazy, right?

This type of software bug is an error that makes the software behave in a way that doesn’t quite match the intended functionality. This type of defect can be spotted pretty easily through functional tests or manual regression tests.

Examples of functional bugs include:

• A login button that doesn’t allow users to login
• An add-to-cart button that doesn’t update the cart
• A search box that doesn’t respond to a user’s query

In simple terms, any component in an app or website that doesn’t function as intended is a functional bug.

How To Manage Them

Testing, testing, testing! Running the software under a number of different conditions and combining the suspicious feature with other features to spot potential differences can help us detect these functional bugs so we can resolve them in the early stages to avoid bad user experiences. 

The development team can write unit tests and integration tests to make sure their code is performing correctly. The QA team can write automated functional tests to ensure that the UI works as planned. They can also perform manual regression tests for areas of the software that are still changing with a higher frequency.

3. Syntax Errors

A syntax error occurs when a command is not written correctly. This may include the presence of a grammatical mistake, a misspelled word or missing symbol, or a syntactical error in your site’s code. This issue can break your website, leaving you with a blank page or error message. And no one wants that.

Let’s take a look at this example of a syntax bug from Wikipedia. In the programming language Java, the following statement is syntactically correct:

System.out.println(“Hello World”);

The following statement is very similar, but it is incorrect and would produce a syntax error:

System.out.println(Hello World);

The only difference between the two statements is the presence of quotation marks around the string “Hello World,” and that one small error is enough to derail the program. Sheeeeeesh. 

How To Manage Them

When a syntax error occurs, you can easily fix it by either removing or correcting the code containing the error. 

But what about preventing syntax errors from happening in the first place? We got you. 

Using proper syntax helps you avoid bugs in the future. PHP is a feature-rich, yet simple, flexible language. You can invest a little time and learn the basics. Then, when you’re pasting code or making edits to your site’s files, you’ll know how to correct bugs as you work.

As another option, you can keep a code editor handy to check syntax before pasting code into your website. This is a smart practice for ensuring that a code snippet is correct before adding it to files on a live site. Another way to prevent issues is to enable debugging when making changes to your site in order to flag errors before going live.

4. Logic Bugs

To put it simply, a logic bug — or semantic bug — is a piece of code that executes properly but does not behave the way you intended. They occur when there is a fault in the logic or structure of the problem. Unlike a program with syntax errors, a program with logic errors can be run, but it does not operate as intended.

Here is a great example of a logic bug: