2.3 Producing Robust Programs

Question 1

What are the 5 Input Validation checks?

Answer 1

Range Check
Type Check
Format Check
Presence Check
Length Check

Question 2

Explain the range check

Answer 2

Checks data is within a certain range, usually numbers

Question 3

Explain the format check

Answer 3

Checks data is entered in a certain way

Question 4

Explain the presence check

Answer 4

Checks data has been entered and not left blank

Question 5

Difference between Input Sanitisation, Validation and Authentication

Answer 5

Input Sanitisation is cleaning up input data to reduce redundancy or remove malicious code.
Validation is checking whether input data follows specific criteria and should be accepted.
Verification is checking whether data that has been entered is correct.

Question 6

What are 5 ways of making a program more maintainable?

Answer 6

1. Using constants,
2. Using subprograms
3. Using indentation
4. Appropriate variable names
5. Add comments
   This improves readability and ease of debugging

Question 7

Give 2-4 reasons for the purpose of testing

Answer 7

1. To ensure there are no bugs
2. To ensure unauthorised access is prevented
3. To check the program has an acceptable performance
4. To check the program meets the requirements

Question 8

Explain a difference between iterative and final testing.

Answer 8

Iterative:
- used when program is being developed
- programmer develops a module and tests it repeatedly until runs as intended
Final:
- used when program is finished
- tests with normal, boundary, invalid and erroneous data
- used only after each module has been tested

Question 9

Define syntax error.

Answer 9

• when there is a mistake in the grammar of the programming language
• the program will not execute

Question 10

Define logic error.

Answer 10

• the program will run/be executed but produces an unexpected output