7.1, 7.2 (w/o loops), 7.5, 7.6 Flashcards
a dog cant talk
the stages of a PDLC (program development life cycle)
4
- analysis,
- design,
- coding
- testing
Analysis
PDLC
identification of the problem and requirements
uses two techniques-
* abstraction,
* decomposition
…of the problem
abstraction
the act of removing unimportant details of the problem to focus on important elements
decomposition
breaks down a complex problem into smaller parts which can then be subdivided and easily solved
Design
how a problem should be executed is planned and documented using
* flowcharts,
* pseudocode
* structure diagrams
Coding
writing the program code and the code is tested, amended and repeated until the module performs as required
testing
testing program code with the use of test data to detect and fix the errors in the program
computer system
PDLC
every computer system is made up of sub-systems, which are made up of further sub-systems
Components of a computer system/results of decomposition (4)
- Inputs
- Outputs
- Processes
- Storage
Top down design
Decomposition of a computer system into subsystems until each system performs a single action
What is data validation?
Validation is an automated check carried out by a computer to make sure the data entered is reasonable
The different types of validation checks
6
- Range checks
- Length checks
- Type checks
- Presence checks
- Format checks
- Check digits
range check
to test if the data input falls between a given upper bound and a given lower bound
length check
To test if the data input is under a certain number of characters
Type Check
To test if the data input is of the correct data type
Pressence check
make sure that input data has been entered and that the input box has not been left empty
Format check
Format checks make sure that input data is of a predefined pattern
What is verification check
To test if the data input is the same as the data that was intended to be input
Vefification check methods
- double entry check
- visual checks
Double entry checking
- Expects each item of data to be entered twice and compares both entries to check they are the same,
- if not the data entry opterator is asked to re-enter data
Visual check
- The user visually checks the data on the screen. A message then asks if the data is correct before proceeding.
- If it isn’t the user then renters the data
For trace tables what does MOD mean
MOD= remainder of your division
For trace tables what does DIV mean
DIV= the answer for your division
Char
data type for single charcter like A, F, G