20 Debugging Interview Questions and Answers

Debugging is a process of identifying and removing errors from a software program. It is a critical skill for any software developer, as it allows them to identify and fix errors in their code. When interviewing for a position in software development, you may be asked questions about your debugging process and skills. In this article, we review some of the most common debugging questions and how you should answer them.

Debugging Interview Questions and Answers

Here are 20 commonly asked Debugging interview questions and answers to prepare you for your interview:

1. What is the difference between debugging and testing?

Debugging is the process of finding and fixing errors in a piece of software. Testing is the process of verifying that a piece of software works as intended.

2. How would you debug code that’s running well in one environment but not in another?

There are a few different ways to debug code that’s running well in one environment but not in another. One way would be to use a debugger tool to step through the code and see where the differences are. Another way would be to compare the two environments and look for any differences that could be causing the issue. Finally, you could also try running the code in a different environment to see if the issue persists.

3. Can you explain what a breakpoint is? When should it be used?

A breakpoint is a point in your code where you want the debugger to pause execution so that you can examine the current state of your program. This can be useful for figuring out why your code is not working as expected. Breakpoints should be used sparingly, as pausing your code too often can make it difficult to get work done. However, they can be very helpful when you are trying to track down a bug.

4. What are the different types of breakpoints available in Visual Studio?

Visual Studio offers several different types of breakpoints:

-Line breakpoints: These breakpoints are set on a specific line of code. The debugger will break execution whenever the line of code is reached.
-Function breakpoints: These breakpoints are set on a specific function. The debugger will break execution whenever the function is called.
-Data breakpoints: These breakpoints are set on a specific data item. The debugger will break execution whenever the data item is accessed.
-Conditional breakpoints: These breakpoints are set with a condition. The debugger will break execution whenever the condition is met.
-Log points: These breakpoints are used to log information to the Output window without breaking execution.

5. What are the steps involved in finding and fixing an issue with your code?

The first step is to identify where the issue is occurring. This can be done by tracing the code execution through the program, or by using a debugger to set breakpoints and step through the code. Once the location of the issue is identified, the next step is to determine what is causing the issue. This can be done by examining the code and looking for errors, or by testing different inputs to see what causes the issue to occur. Once the cause of the issue is determined, the next step is to fix the code so that it no longer causes the issue. Finally, the code should be tested to ensure that the issue has been fixed and that no new issues have been introduced.

6. How do you debug memory leaks in Javascript?

There are a few different ways to debug memory leaks in Javascript. One way is to use a memory leak detector, which will scan your code for potential leaks. Another way is to use a profiler, which will help you identify which parts of your code are using the most memory. Finally, you can also try to manually identify leaks by looking for patterns in your code that might be causing them.

7. How can you use Chrome Developer tools to debug client-side issues?

The Chrome Developer Tools can be used to debug client-side issues in a number of ways. For example, you can use the Developer Tools to inspect the HTML and CSS of a page to find out why a particular element is not being displayed as you expect. You can also use the Developer Tools to step through JavaScript code line by line to find out where an error is occurring.

8. How can you use GDB to debug C/C++ applications?

GDB can be used to debug C/C++ applications by first compiling the code with the -g flag to include debugging information. Then, GDB can be run on the executable file with the desired breakpoints. Finally, the application can be run within GDB to stop execution at the breakpoints and allow for inspection of variables and memory.

9. Why do you think some bugs never get fixed?

There are a few reasons why some bugs never get fixed. The first reason is that the bug may not be reproducible, which makes it difficult to track down and fix. The second reason is that the bug may be in a part of the code that is not frequently used, so it may not be discovered until it is too late to fix. The third reason is that the bug may be caused by a third-party library or component that the developers do not have control over, so they are unable to fix it.

10. When should we use conditional breakpoints instead of regular ones?

Conditional breakpoints are best used when you want to break execution only when a certain condition is met. For example, if you want to break only when a variable reaches a certain value, you would set a conditional breakpoint. If you want to break every time a certain line of code is executed, then you would set a regular breakpoint.

11. What does “stepping into” mean in context with debugging?

Stepping into is a debugging technique where you execute a line of code one instruction at a time. This allows you to see exactly what is happening and track down any errors.

12. What does “stepping over” mean in context with debugging?

Stepping over is a debugging technique where you execute a line of code without actually entering into the function that it calls. This can be useful if you want to quickly get to a certain point in your code without having to step through all of the code in between.

13. How is stepping through code different from using breakpoints?

Stepping through code is a process of going line by line through the code in order to find the source of an error. This can be done manually, or with the help of a debugger. Breakpoints are specific lines in the code that you can set in order to pause the execution of the code at that point. This can be helpful in pinpointing the location of an error.

14. What do you understand about stack overflows?

A stack overflow is a type of error that can occur when a program tries to push too much data onto the stack. This can happen if the program is not designed properly, or if it is trying to process too much data at once. If a stack overflow occurs, it can cause the program to crash or freeze.

15. What are the differences between exception handling and debugging?

Exception handling is a process of dealing with errors that occur during the execution of a program. This can involve either ignoring the error and continuing on, or terminating the program entirely. Debugging, on the other hand, is the process of finding and fixing errors in a program. This can be done either manually or with the help of a debugger, which is a tool that helps you find and fix errors in your code.

16. How do you debug .NET code?

There are a few different ways to debug .NET code. One way is to use the Visual Studio debugger. Another way is to use a tool like WinDbg.

17. What is the best way to debug multiple threads at once?

The best way to debug multiple threads at once is to use a tool like the Java Platform Debugger Architecture. This tool will allow you to suspend and resume all threads at the same time, so that you can investigate the state of the program and figure out where the problem is.

18. What is the difference between a deadlock and live lock? Which one is easier to detect and fix?

A deadlock is when two threads are each waiting on the other to release a lock. A livelock is when two threads are each trying to acquire a lock that the other thread is holding. Deadlocks are easier to detect because they cause the threads to block. Livelocks are harder to detect because the threads are still active, but they are not making progress.

19. What is the process for debugging programs on embedded systems?

The process for debugging programs on embedded systems can vary depending on the system and the tools that are available. However, some common steps include using a debugger to connect to the system, setting breakpoints, and then running the program until it hits a breakpoint. At that point, you can examine the state of the system and try to determine what is causing the issue.

20. What do you understand by concurrency bugs? Can they be prevented?

Concurrency bugs are errors that occur when two or more threads of execution are trying to access the same data at the same time. These bugs can be prevented by using synchronization techniques to ensure that only one thread can access the data at a time.