The Principles of Debugging: Easy How-To Steps

By Adeline Ishimwe

The term debugging is used in various ways across various disciplines, but let’s focus on the programming world. 

What is debugging?

Debugging is the process of identifying and fixing existing and potential errors in a written code that can lead to unwanted output or performance. These errors are usually referred to as “bugs,” thus, the process of removing them is “debugging.” 

Recommended reading: Interested in learning where the term “bug” originated? Read this interesting article from Curiousity.com

In order to get your code to deliver the desired output, it must be free of any defects or bugs. 

Note: Bugs are sub-categories of defects. A defect is simply a variance between expected and actual.

Types of Errors


Errors can be differentiated by looking at the source. Syntax errors are an error caused by the inability of the computer to understand what the user is saying. It could be a spelling error or a command that the computer doesn’t understand.


This type is a common headache for programmers. This is when the computer understands what the user is asking, but the output is different from what the user expected.

While there are multiple approaches to debugging, below are some common steps to successful steps.

How to Debug a Program

Step 1

Identify the problem and decide which debugger to deploy.

To debug a program, the programmer must understand the problem and be very familiar with the desired output of the program.

Your debugging tools are equipped to reproduce the conditions in which errors have occurred, so make use of them! This will help the programmer examine the program state at any time and find those pesky bugs.

Depending on the intended purpose, some widely used debuggers are:

  • Radare2
  • WinDbg 
  • Valgrind 
  • Microsoft Visual Studio Debugger
  • LLDB debugger
  • Valgrind
  • Eclipse debugger

In some cases, the user may need to use a virtual machine to use some of these programs. 

Step 2

Set an intentional stopping or pausing place in a program, known as a breakpoint, and run the code using the selected debugger.

Step 3

Examine the outcomes of the variables associated with the code and ask yourself, “Is this the desired outcome?”

Step 4

If the results are not as expected, make the required changes and run the code again.

If the actual output differs from the expected output, then you must use the available debugging tools to identify errors at multiple developmental stages. This could include spelling checks, variable mismatch, or logic verification.

For instance, if the error is in compiling time, then check misspellings. Every problem stems from somewhere, you just have to find it.

Step 5

If step 4 is done correctly, the software will stop at another breakpoint, otherwise it will stop on the same one. If it doesn’t proceed to the next breakpoint, repeat steps 3, 4 and 5.

Step 6

If you have successfully debugged the code at this breakpoint, repeat the process within the other breakpoints until the whole code is running successfully.

Have any debugging tips of your own?

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