Debugging and errors

Course Outline: Debugging and Errors

Module 1: Introduction to Debugging

• What is debugging?
  • Definition of debugging and its importance in programming.
  • The debugging process: identifying, diagnosing, and fixing bugs in code.
  • Why debugging is a crucial skill for programmers.
• Types of errors in programming
  • Syntax errors: mistakes in the structure of the code (missing parentheses, commas, etc.).
  • Runtime errors: errors that occur during the execution of a program (e.g., division by zero).
  • Logical errors: errors in the program’s logic that result in incorrect output, but no crash.

Module 2: Common Types of Errors

• Syntax errors
  • How to identify syntax errors and fix them.
  • Example: fixing common syntax mistakes like missing semicolons or mismatched parentheses.
  • How to use error messages to understand the issue.
• Runtime errors
  • Understanding runtime errors: division by zero, null pointer dereferencing, etc.
  • Example: how to handle potential runtime errors (e.g., using conditionals to prevent divide by zero).
• Logical errors
  • What are logical errors and how they differ from other types of errors.
  • Example: debugging a program with incorrect output due to flawed logic (e.g., incorrect calculations).
  • How to approach finding logical errors systematically.

Module 3: Debugging Tools and Techniques

• Using print statements for debugging
  • How print statements can be used to track variable values and program flow.
  • Example: adding print statements to a function to verify the input/output at each step.
• Using a debugger
  • What is a debugger? Introduction to debugging tools (e.g., built-in debuggers in IDEs).
  • How to set breakpoints, step through code, and inspect variable values during execution.
  • Example: using a debugger to find where the program is breaking and identifying the faulty logic.
• Error logs and stack traces
  • How to interpret error logs and stack traces to identify the cause of runtime errors.
  • Understanding stack trace output: where the error occurred and the function calls leading to it.
  • Example: reading a stack trace to pinpoint the source of an exception.

Module 4: Strategies for Effective Debugging

• Divide and conquer debugging
  • Breaking down the code into smaller sections to isolate the source of the error.
  • Example: commenting out large blocks of code to narrow down the problem area.
• Rubber duck debugging
  • What is rubber duck debugging and how explaining the problem out loud can help clarify the issue.
  • Example: discussing the logic with someone or even an inanimate object to identify flaws in reasoning.
• Reproduce the error
  • How to consistently reproduce the error, which makes it easier to identify the cause.
  • Example: identifying the exact conditions under which a bug occurs.

Module 5: Best Practices in Debugging

• Write readable and maintainable code
  • How clean, well-structured code can help prevent errors and make debugging easier.
  • Best practices: meaningful variable names, proper indentation, clear logic flow.
• Test-driven development (TDD) and debugging
  • Introduction to test-driven development (TDD) and how writing tests first can prevent many bugs.
  • Example: writing unit tests to catch errors early and simplify debugging.
• Unit testing and debugging
  • Using unit tests to isolate problems in specific parts of the code.
  • Example: running unit tests to validate the correctness of a function or module.

Module 6: Debugging Complex Programs

• Debugging multi-threaded applications
  • Introduction to debugging programs with multiple threads or processes.
  • Challenges of multi-threaded debugging: race conditions, deadlocks.
  • Example: using thread-safe debugging techniques to troubleshoot multi-threaded programs.
• Memory management issues
  • How to debug issues related to memory allocation and deallocation.
  • Example: debugging memory leaks or accessing invalid memory locations.
  • Tools for memory debugging (e.g., Valgrind).
• Network-related bugs
  • Identifying and fixing bugs related to network communication (timeouts, broken connections).
  • Tools and techniques for debugging network-related issues.

Module 7: Advanced Debugging Techniques

• Reverse debugging
  • What is reverse debugging? How to go backward through the program to identify when the error occurred.
  • Tools for reverse debugging and their use cases.
• Profiling and performance debugging
  • How to use profiling tools to identify performance bottlenecks.
  • Example: debugging slow code by finding time-consuming functions and optimizing them.
• Handling exceptions and errors gracefully
  • How to catch and handle exceptions using try, catch, finally.
  • Example: implementing robust error-handling to prevent crashes and provide meaningful error messages to users.

Module 8: Debugging in Practice

• Hands-on exercises
  • Debugging common coding challenges: identifying and fixing errors in sample code.
  • Example: fixing a program that calculates the factorial of a number but contains a logical error.
• Debugging a real-world application
  • Work on debugging a complete project: finding and fixing bugs in a project with multiple files and complex logic.
  • Example: debugging a simple game or a calculator program with various issues.
• Final debugging project
  • Provide a buggy project for students to debug, applying all the techniques learned in the course.

Module 9: Conclusion and Final Tips

• Recap of the debugging process
  • Key steps in debugging: identifying, isolating, fixing, and testing.
  • Reviewing debugging tools and strategies that are most useful in various scenarios.
• Debugging as a continuous skill
  • How debugging is an ongoing learning process: always improving with experience.
  • Tips for staying patient and systematic when debugging complex issues.

Additional Materials:

• Video tutorials: Demonstrations of common debugging techniques and tools.
• Quizzes and assessments: Short quizzes to reinforce debugging concepts and error types.