Records

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Revision as of 17:07, 6 January 2010 by Kees (talk | contribs)

5E - Records (author: Tao Yue, state: unchanged)

A record allows you to keep related data items in one structure. If you want information about a person, you may want to know name, age, city, state, and zip.

To declare a record, you'd use: <delphi> TYPE

 TypeName = record
   identifierlist1 : datatype1;
   ...
   identifierlistn : datatypen;
 end;

</delphi>

For example: <delphi> type

 InfoType = record
   Name : string;
   Age : integer;
   City, State : String;
   Zip : integer;
 end;

</delphi>

Each of the identifiers Name, Age, City, State, and Zip are referred to as fields. You access a field within a variable by: <delphi>

VariableIdentifier.FieldIdentifier

</delphi>

A period separates the variable and the field name.

There's a very useful statement for dealing with records. If you are going to be using one record variable for a long time and don't feel like typing the variable name over and over, you can strip off the variable name and use only field identifiers. You do this by: <delphi> WITH RecordVariable DO BEGIN

 ...

END; </delphi>

Example: <delphi> with Info do begin

 Age := 18;
 ZIP := 90210;

end; </delphi>

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