Computer Science

Topic 4 - Data Representation & Data Types

What you need to know:-

Data types - Describe the following different primitive data types, Boolean, character,
string, integer and real.

- Describe the storage requirements for each data type.

Primitive Data Types - There are FIVE primitive data types, which can be used in programming languages to declare and store different types of information.

Most programming languages have their own versions of the five primitive data types outlined below. For example, in Visual Basic, you can store decimal values in a Single or Double data type - these are just versions of the REAL primitive data type. In a theory exam, you would always answer with a primitive data type, not one that is specific to a programming language.

STRING

This is the most common data type, almost anything which has letters, numbers, symbols, punctuation, or a combination of all of these, can be stored as STRING

Examples: Surname = "Smith", Telephone Number = "07989123456", CarReg = "CF13 ABC", Message = "Please enter a number!"

CHARACTER

This data type is used when you only want to store a single letter, or a digit which is not a number you would perform a calculation on.

Examples: Gender = "M", Gender = "F", Assessment Marker Effort = "2"

INTEGER

This is the simplest data type to use, when you only want to store a whole number (NOT a decimal). This number would usually be something you would perform a calculation on. As such, INTEGER would NOT be used for a telephone number.

Examples: NoOfCars = 65, NoOfSiblings = 2, NoInStock = 100

REAL

This data type is used to store decimal numbers.

Examples: TreeHeight = 1.2, Cost = 200.70, Average = 7.56

BOOLEAN

This is a special data type, which only has one of two values. The values are opposites and include the following only: Yes or No, True or False, 0 or 1, On or Off

Examples: Delivery = Yes, Smoker = No, RecordFound = True, Errorfound = False

Page updated

Report abuse