Testing and Debugging
Testing finds errors in a program and debugging fixes them, using methods such as test data and trace tables.
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Testing finds errors in a program and debugging fixes them, using methods such as test data and trace tables.
- Syntax errors break the rules of the language
- Logic errors give wrong results
- Trace tables follow variable values
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is Testing and Debugging?
Within Computer Science, which covers algorithms, programming, data, networks, hardware and safe, responsible use of technology, this topic explains Testing and Debugging. Computing topics explain how software, hardware and data work, with diagrams and models that show each step in order.
Check that you can explain Testing and Debugging in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding Testing and Debugging helps you design, test and explain programs, websites and systems, from small projects to exam questions.
Testing and Debugging in detail
Testing checks whether a program works correctly. Test plans use different types of data: normal (expected values), boundary (at the limits of what is acceptable) and erroneous (invalid data that should be rejected), with expected and actual results compared. Iterative testing happens during development, and final or acceptance testing at the end.
Debugging is finding and fixing errors. Methods include reading the error messages, tracing the code by hand with a trace table, adding print statements, using a debugger with breakpoints and testing small parts. Good testing finds bugs early, when they are cheaper to fix, and builds confidence that the program does what it should.
How the interactive helps you understand Testing and Debugging
Click a step, or use the Previous and Next buttons, to move through the sequence one stage at a time. Auto-play moves on for you.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Testing and Debugging.
Real-life uses and examples
- Recognise Testing and Debugging in an app or device you use every day.
- Apply Testing and Debugging when you design a small program, website or spreadsheet.
- Explain Testing and Debugging to someone new to computing by comparing it to a familiar process.
Common mistakes to avoid
- Using the term without being able to say what the computer actually does.
- Testing only the normal case and forgetting the edge cases.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about Testing and Debugging
What is Testing and Debugging?
Testing finds errors in a program and debugging fixes them, using methods such as test data and trace tables.
What are the most important points about Testing and Debugging?
The main points are: Syntax errors break the rules of the language; Logic errors give wrong results; Trace tables follow variable values.
Why is Testing and Debugging useful?
Understanding Testing and Debugging helps you design, test and explain programs, websites and systems, from small projects to exam questions.
How can I practise Testing and Debugging?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to Testing and Debugging?
Related topics in Computer Science include Sorting Algorithms, Programming Paradigms, Compilers and Interpreters.