Record Structures (Cambridge (CIE) A Level Computer Science): Revision Note

Purpose of records

What is a record?

• A record is a composite data structure used to store a collection of related data items

• Each item can be of a different data type

• It allows a programmer to group related values under one identifier

• Records help create a more structured and readable approach to storing and managing data

• A record contains a fixed number of fields, each with its own name and type

• In pseudocode, a record can by declared as:

TYPE <Typename>
    DECLARE <identifier> : <data type>
    DECLARE <identifier> : <data type>
    DECLARE <identifier> : <data type>
    ..
    ..
ENDTYPE

• Suppose we want to store information about a car

• We can define a record type like this:

TYPE Car
    DECLARE Make : STRING
    DECLARE Model : STRING
    DECLARE Colour : STRING
    DECLARE Price : REAL
    DECLARE DateOfRegistration : DATE
ENDTYPE

• We can then create a variable of this type:

DECLARE MyCar : Car

• And assign values to its fields:

MyCar.Make ← "Toyota"
MyCar.Model ← "Yaris"
MyCar.Colour ← "Red"
MyCar.Price ← 14995.99
MyCar.DateOfRegistration ← "12/03/2022"

• To read from the record we can:

OUTPUT "Make: ", MyCar.Make
OUTPUT "Model: ", MyCar.Model
OUTPUT "Colour: ", MyCar.Colour
OUTPUT "Price: £", MyCar.Price
OUTPUT "Date of Registration: ", MyCar.DateOfRegistration

Key features of records