Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

  ◄Keywords► ◄Contents► ◄Index►                                   ◄Back►
 
  CASE   <tag field>  OF  <variant list>
 
  Description
 
    Every record has an optional field called a variant field. A
    variant field, if it exists, is always the last field of a record;
    it allows one field to store one of several data types. The
    compiler sets aside enough memory to hold the largest data type
    that the resulting variant field can hold.
 
    The variant part begins with the CASE keyword and contains a
    <tag field> and a <variant list> separated by the OF keyword.
 
  The <tag field>
 
    [ <identifier> : ] <ordinal type>
 
    The <tag field> can begin with an optional identifier and colon.
    The identifier must be of an ordinal type such as Boolean,
    enumerated, or subrange types.
 
  The <variant list>
 
    <constant> [, <constant>, ... ]  :  ( [ <field list> ] );
                              .
                              .
    <constant> [, <constant>, ... ]  :  ( [ <field list> ] )
 
    A <variant list> contains one or more comma separated variant
    fields. Each variant field contains one or more comma separated
    constants, a colon, and a <field list>. The <field list> is
    contained in parenthesis.
 
  The <field list>
 
    <identifier> [, <identifier>, ... ] : <any type>
 
    The <field list> is what the variant record actually stores. It
    contains one or more comma separated field declarations. Each
    field declaration contains one or more comma separated
    identifiers, a colon, and a type designator.
 
  See also:  Data Types Hierarchy