Revise Computing
Revision notesQuestionsFor schools
Log inStart revising free
Revision notesQuestionsFor schoolsLog in
GCSE Computer Science/Supplementary programming practice/IDE Skills

Debugging tools

301.18 IDE Skills

Practise exam questions

IDE Skills — Note 4 of 4

Stepping + watch tools.

What you need to know

IDEs offer debugging tools: breakpoints pause the program at a specific line, stepping runs one line at a time, and watch windows show variable values as the program runs.

What to know

  • Breakpoint: click the line margin to set a pause point
  • Step Over (`F10`): run one line, skip into functions
  • Step Into (`F11`): go inside a function call
  • Watch: add a variable to see its value update live
  • Use these to trace logic errors without print()

Code examples

Debugging workflow
python
# 1. Set breakpoint on suspicious line
# 2. Run in debug mode
# 3. Step through line by line
# 4. Watch variable values change
# 5. Find where the value goes wrong

total = 0
for i in range(5):    # ← set breakpoint here
    total += i        # watch 'total' and 'i'
← Previous noteRunning code301.18 IDE Skills

Back to IDE Skills

Specification notes for programming are in Paper 2.

IDE Skills

Note 4 of 4

  1. 1Editor usage
  2. 2Error messages
  3. 3Running code
  4. 4Debugging tools
Topic overview

© 2026 Revise Computing · revisecomputing.co.uk

Privacy noticeTermsContact

Revise Computing is an independent revision resource. It is not affiliated with, or endorsed by, OCR (Oxford Cambridge and RSA Examinations).