2.3 - Producing Robust Programs

Question 1

What is considered when creating a secure and robust program?

Answer 1

• Anticipating misuse
• Input sanitisation
• Validation
• Verification
• Authentication
• Maintainable code

Question 2

What is anticipating misuse?

Answer 2

Planning ahead to take steps against potential misuse

Question 3

What is input sanitisation?

Answer 3

Cleaning up data that has been input by removing non-standard characters

Question 4

What is validation?

Answer 4

Checking whether input data follows specific criteria to be accepted

Question 5

What is verification?

Answer 5

Checking whether data that has been entered is correct

Question 6

What is authentication?

Answer 6

Ensuring only authorised users can gain access to a system

Question 7

What is maintainable code?

Answer 7

Code that is readable for other programmers

Question 8

What should be considered when creating maintainable code?

Answer 8

• Using comments so others can understand the purpose of each line of code
• Indentation to improve readability
• Appropriate variable names
• Using subprograms to reuse code and make them easier to test

Question 9

What is the purpose of testing?

Answer 9

To check that:
- Program works correctly no matter what input has been entered
- To check there are no errors
- User requirements met
- Acceptable performance and usability
- Unauthorised access prevented

Question 10

What is iterative testing?

Answer 10

The testing of modules repetitively throughout development

Question 11

What is terminal/final testing?

Answer 11

Testing that all modules work together (integration testing) at the end of development

Question 12

What is a syntax error?

Answer 12

A grammatical mistake or a mistake in the rules of the programming language that means a program can’t run

Question 13

What is a logic error?

Answer 13

A mistake by the programmer where the program runs but will display an incorrect or unexpected output

Question 14

What are the four types of test data?

Answer 14

• Normal data
• Boundary data
• Invalid data
• Erroneous

Question 15

What is normal data?

Answer 15

Data that the program should accept without causing errors because it is within the validation limit

Question 16

What is boundary data?

Answer 16

Data of the correct type which is on the edge of accepted validation limits.

Question 17

What is invalid data?

Answer 17

Data of the correct data type that does not meet the validation rules and shouldn’t be accepted

Question 18

What is erroneous data?

Answer 18

Data of the wrong data type that the program cannot process and should not accept