The Importance of Debugging
- Debugging is the process of identifying and fixing errors in your code.
- It ensures that your program behaves as expected and is a critical skill for any programmer.
Debugging is not just about fixing errors, it's about understanding how your code works and improving its overall quality.
Common Debugging Techniques
- Trace Tables
- Breakpoint Debugging
- Print Statements
- Step-by-Step Code Execution
- When debugging, always start by identifying the type of error: syntax, runtime, or logic.
- This will guide you in choosing the most effective debugging technique.
Trace Tables
- Trace tables are used to manually track the values of variables as an algorithm executes.
- They help identify logic errors by showing how data changes over time.
Counting Warm Days
Consider the following Python code that counts the number of warm days (temperatures above 20°C):
| Iteration | Value of temp | warmDays |
|---|---|---|
| 1 | 23.7 | 1 |
| 2 | 19.9 | 1 |
| 3 | 23.8 | 2 |
| 4 | 18.8 | 2 |
| 5 | 12.5 | 2 |
| 6 | 24.0 | 3 |
Trace tables are especially useful for understanding loops and conditional statements, where variable values change frequently.
Breakpoint Debugging
- Breakpoints are markers set in your code that pause execution at specific points.
- This allows you to inspect variable values and program flow.
How to Use Breakpoints
- Set a Breakpoint: Place a breakpoint at a line of code where you want to pause execution.
- Run the Program: Execute the program in a debugger. It will pause at the breakpoint.
- Inspect Variables: Check the values of variables and the program state.
- Continue Execution: Step through the code line by line or resume normal execution.
- Use breakpoints to isolate specific sections of code, especially in large programs.
- This helps you focus on the part of the code that may be causing issues.
Print Statements
Print statements are a simple yet effective way to debug by displaying variable values and program flow in the console.
