What is the letter called which replaces a Boolean expression?
Boolean Variable
What are the Boolean variables either?
True or False
What is a truth table?
Representation of the logic showing the output, given each possible input
Why is authentication used?
Make sure that a person is who they say they are
What are examples of methods of authentication?
- Optical Recognition
- Facial Recognition
- Fingerprint Recognition
Why are you normally only allowed three attempts to type in the correct password?
Protect system from unauthorised access
What are examples of validation check?
- Range: Number within range
- Type: Data type
- Length: Text entered too long
- Presence: Data has been entered
- Format: e.g. postcode
What can validation only check?
- If it is reasonable, not correct
What is verification?
Double-check data has been typed correctly
- Two version compared
What are ways of making program code understandable?
- Subprograms
- Naming Conventions
- Indentation
- Comments
What are syntax errors?
- Where translator expects commands to have a certain format, so without it won’t be able to translate it into machine code
What is a logic error?
- Once no syntax errors, it can be run.
- Logic error is where program doesn’t do what is expected
Types of testing
- Iterative (Subroutine tested separately when written)
- Terminal (Program finished and works)
What should test data include?
- Normal
- Boundary
- Invalid
- Erroneous
What is a trace table?
Tracks how a value of a variable changes
What are the two types of languages?
- High-Level
- Low- Level
When is assembly language often used?
Embedded Systems
What is an assembler?
- Converts assembly language to machine code
What is a compiler?
- Translates program written in high-level programming language to machine code
What is an interpreter?
Also translates high-level language to machine code, but translates each line of source code and executes
What does the IDE do?
- Enter, edit and save source code
- Identify and correct syntax errors
- Translate source to machine code
- Execute program
