Debugging
Names and abbreviations on this page
MDN — MDN Web Docs (formerly Mozilla Developer Network). Reference material for web programming.
Programming terms & practical skills
What it means
Debugging is the process of finding, understanding and correcting faults in software. A useful investigation starts with a reproducible problem and evidence. Testing can reveal a failure; debugging investigates why it happened.
Related skills
Reproduce clearlyRecord the input, action and observed result.
Narrow the causeChange one relevant factor at a time.
Verify the correctionRepeat the original case and check nearby behavior.
An everyday example
A calculator gives 1200150 where 1350 was expected. Inspect the input types before rewriting the formula. After correcting the conversion, repeat the example and check a blank input too.
What to check
Preserve a working copy before editing. A change that hides one symptom may leave the underlying problem unresolved.