Difference between revisions of "Record"
| Line 1: | Line 1: | ||
{{Record}} | {{Record}} | ||
| − | |||
| − | While simple data structures such as arrays or sets consist of elements all of the same type, a record can consist of a number of elements of different types, and can take on a huge complexity. Each separate part of a record is referred to as a Field. | + | A highly structured data [[Type|type]] in [[Pascal]] . |
| + | |||
| + | While simple data structures such as [[Array|arrays]] or sets consist of elements all of the same type, a record can consist of a number of elements of different types, and can take on a huge complexity. Each separate part of a record is referred to as a Field. | ||
Some examples of records: | Some examples of records: | ||
| + | <delphi> | ||
Type | Type | ||
ExampleRecord = Record | ExampleRecord = Record | ||
| Line 20: | Line 22: | ||
PaidCurrentSubscription: Boolean | PaidCurrentSubscription: Boolean | ||
End; | End; | ||
| + | </delphi> | ||
A record is treated by the program as a single entity, and for example a whole record can be copied (provided the copy is of the same type) thus: | A record is treated by the program as a single entity, and for example a whole record can be copied (provided the copy is of the same type) thus: | ||
| + | <delphi> | ||
Var a, b : Member; | Var a, b : Member; | ||
Begin | Begin | ||
| Line 30: | Line 34: | ||
b := a | b := a | ||
End; | End; | ||
| + | </delphi> | ||
Individual fields are accessed by placing a dot between the record name and the field name thus: | Individual fields are accessed by placing a dot between the record name and the field name thus: | ||
| + | <delphi> | ||
a.firstname := 'George'; | a.firstname := 'George'; | ||
a.surname := 'Petersen'; | a.surname := 'Petersen'; | ||
a.phone := 789534; | a.phone := 789534; | ||
a.PaidCurrentSubscription := TRUE; | a.PaidCurrentSubscription := TRUE; | ||
| + | </delphi> | ||
| − | Alternatively, the whole series of fields can be made available together using the WITH construct: | + | Alternatively, the whole series of fields can be made available together using the [[With|WITH]] construct: |
| + | <delphi> | ||
with a | with a | ||
do | do | ||
| Line 46: | Line 54: | ||
PaidCurrentSubscription := TRUE | PaidCurrentSubscription := TRUE | ||
end; | end; | ||
| − | + | </delphi> | |
Records are widely used in Pascal, to group data items together logically. | Records are widely used in Pascal, to group data items together logically. | ||
Revision as of 07:12, 22 July 2008
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A highly structured data type in Pascal .
While simple data structures such as arrays or sets consist of elements all of the same type, a record can consist of a number of elements of different types, and can take on a huge complexity. Each separate part of a record is referred to as a Field.
Some examples of records:
<delphi>
Type
ExampleRecord = Record
Values: array [1..200] of real;
NumValues: Integer; { holds the actual number of points in the array }
Average: Real { holds the average or mean of the values in the array }
End;
Member = Record
Firstname, Surname : string;
Address: array [1..3] of string;
Phone : Integer;
Birthdate: TDateTime;
PaidCurrentSubscription: Boolean
End;
</delphi>
A record is treated by the program as a single entity, and for example a whole record can be copied (provided the copy is of the same type) thus:
<delphi>
Var a, b : Member;
Begin
{ assign values to the fields in Record a }
...
...
b := a
End;
</delphi>
Individual fields are accessed by placing a dot between the record name and the field name thus: <delphi>
a.firstname := 'George'; a.surname := 'Petersen'; a.phone := 789534; a.PaidCurrentSubscription := TRUE;
</delphi>
Alternatively, the whole series of fields can be made available together using the WITH construct: <delphi>
with a
do
begin
firstname := 'George';
surname := 'Petersen';
phone := 789534;
PaidCurrentSubscription := TRUE
end;
</delphi>
Records are widely used in Pascal, to group data items together logically.
