Learn Pascal
5E - Records

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

For example:

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

Each of the identifiers Name, Age, City, State, and Zip are referred to as fields. You access a field within a variable by:
     VariableIdentifier.FieldIdentifier
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 type the variable name over and over, you can strip off the variable name and use only field identifiers. You do this by:
     WITH RecordVariable DO
        BEGIN
           ...
        END;

Example:

   WITH Info DO
      BEGIN
         Age := 18;
         ZIP := 90210;
      END;


Previous lesson

Next lesson

Contents

Index

e-mail me


taoyue@mit.edu
Copyright © 1997-2001 Tao Yue. All rights reserved.