The short answer
Define inputs, outputs and exclusions before building a minimal version. Real business use requires ownership of operation and maintenance.
Try it in three steps
- Choose an offline practice task such as removing blank lines.
- Ask for the approach and files affected.
- Test ordinary, empty and unusual inputs.
A practice prompt
Before you start
Ask for an explained single-file HTML exercise. Check for external scripts before saving as demo.html and opening locally.
Practice material (fictional)
Use two text areas and a remove-blank-lines button. Input apple, a blank line and pear. No network, accounts, installers or payments.Replace placeholders in the prompt with this material, or append the material if there are no placeholders. Reading time excludes doing the exercise.
Create a local blank-line remover without uploads or accounts. List files and checks before providing minimal code.What to look for (not a recorded test result)
The output should contain apple and pear on two lines; empty input stays empty. This does not establish general file handling or production readiness.
If it goes wrong
If it adds a database or payments, narrow back to the single practice function.
Check your result
You can run, stop and check it, and name untested cases.
References and scope
The links below support the concepts or product navigation. The steps and exercises are our teaching suggestions, not official certification or measured customer outcomes. Product interfaces and availability may change. References checked on 2026-10-17.