Records


	Home	Back	Topics	CD Orders	INDEX

Records

A record consists of a number of fields.

A field consists of a single data item and these may be of different types. For example a record may consist of three fields :

Field name	Field type
Name	String
Form	String
ExamMark	Integer

When used in programs, the name and type of each field will need to be declared.

Example

In high level languages we need to set up a record type (PupilType) which defines the fields and field types...... and then declare a variable (Pupil) to be of that type:

PupilType = record
	Name : string;
	Form : string;
	ExamMark : integer;
	end;

var Pupil : PupilType;

Values for each field can then be assigned...

Pupil.Name := 'Jimmy Nutten';

Pupil.Form := '12G'

Pupil.ExamMark := 85;

Sample A Level Question
(Click on answer box to reveal sample answer)

The sales department of a small company uses a computer system to store information about all its sales staff.

(a) One file contains the employee number, name, date of birth and address of each salesperson.

(i) Use this example to explain the difference between the two terms field and record.

A record would consist of all the details about one staff member.
The data items in the record are the fields. There are 4 fields in each record - employee number, name, date of birth and address.

(ii) What is the advantage of a record over an array?

A record may have data items of different types but an array must have all its elements of the same type.

(b) Outline an application in this system which might use:

(i) a two dimensional array;

A sales analysis for each employee and for each day of the week. The subscripts would be the days of the week and the sales employee number.

(ii) a three dimensional array;

The analysis in (ii) could be extended to cover a number of weeks. The subscripts would be the days in the week, the sales employee numbers and the week numbers.