Testing, errors and test data

Overview

Iterative and final testing, syntax and logic errors, normal, boundary, invalid and erroneous test data with worked examples, and writing a test plan.

What you need to know

Answer each one before you reveal it.

Questions from this subtopic

Each one with the model answer underneath.

1. 1

   What is the purpose of testing a program?

   Model answer

   Testing finds errors so they can be fixed before the program is used. Testing also shows whether the program meets its requirements and copes with unexpected input.

2. 2

   What is iterative testing?

   Model answer

   Iterative testing checks each module of a program while the program is being developed. The module is retested after every change until it works.

3. 3

   What is final, or terminal, testing?

   Model answer

   Final testing checks the complete program once development has finished. The whole program is tested against its original requirements.

4. 4

   Why is final testing still needed if every module passed iterative testing?

   Model answer

   Modules that work alone can still fail when they are combined. Final testing also confirms the finished program does everything it was designed to do.

5. 5

   What is a syntax error?

   Model answer

   A syntax error is code that does not follow the rules of the language, so it cannot be translated or run. A misspelt keyword such as prnt is one example.

6. 6

   What is a logic error?

   Model answer

   A logic error lets the program run but makes it give the wrong result. An example is a loop that stops one pass early, so the last item is never processed.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.