What's a debugger?
During your journey as a developer, there's always that moment when you end up asking yourself "Why isn't my code working?"
Why isn't my code working?
During your work on the Tailwind Traders retail application, you'll most likely be confronted with this situation a few times. When there's a bug in the program, everyone usually has their own way of dealing with the problem.
You've probably already tried one or more of these debugging approaches yourself:
- Try running your program again because it should work.
- Explain your issue to your colleague.
- Read through your code again to find out the issue.
- Take a walk outside.
- Add a few
console.log('here')in your code.
While you might have various degrees of success with these methods, there's one other approach commonly regarded as being more often successful: using a debugger. But what's a debugger exactly?
A debugger is a software tool used to observe and control the execution flow of your program with an analytical approach. The design goal is to help find the root cause of a bug and help you resolve it. The debugger works by either hosting your program in its own execution process, or running as a separate process that's attached to your running program, like Node.js.
Debuggers come in different varieties. Some work directly from the command line, while others come with a graphical user interface. In this module, we'll use both the built-in command-line debugger that comes with Node.js, and the integrated graphical debugger of Visual Studio Code.
Why use a debugger?
If you're not running your code through a debugger, that means you're probably guessing what's happening in your program. The primary benefit of using a debugger is that you can watch your program running. You can follow your program execution one line of code at a time. In this way, you avoid the chance of guessing wrong.
Every debugger has its own set of features. The two most important features that come with almost all debuggers are:
- Control of your program execution. You can pause your program and run it step by step, which allows you to see which code is executed and how it affects your program's state.
- Observation of your program's state. For example, you can look at variable values and function parameters at any point during your code execution.
Mastering a debugger makes you more efficient at hunting bugs in your code by helping you quickly understand how a program works.
Let's discover that in the next section.