Derived Data Types

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Chapter 12

• Derived Data Types

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Derived Data Types

• User-defined data types used to meet the
  requirements of a specific problem.
• Made of a combination of intrinsic data types
  (integer, real, character, logical, or complex)
  and/or other user-defined data types.

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Form of Derived Data Type Definition

• General form
• TYPE type_name
• component definitions
• . . .
• END TYPE type_name

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Example of Data Definition

• TYPE employee
• CHARACTER (20) lastName
• CHARACTER (20) firstName
• CHARACTER (10) workID
• INTEGER age
• REAL salary
• END TYPE employee

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Examples of Data Defined as a Derived Type

• TYPE (employee) harry, joe
• TYPE (employee), DIMENSION (200)
• firstShift

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Structure Constructor

• Each item of a derived data type is known as a
  structure.
• To create unnamed constants of a derived data
  type, use a structure constructor.
• A structure constructor consists of the name of
  the type followed by the components of the
  derived data type in parentheses.

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Example of Structure Constructor

• harry employee (Jones, Harry,
• 425, 45,
  1200.00)
• joe employee (Smith, Joe, 3356,
• 36, 980.00)

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Example of derived data type within another
derived data type

• TYPE payroll
• TYPE (employee) programmer
• CHARACTER (20) classification
• REAL vacationHours
• REAL sickLeave
• REAL payrollHours
• END TYPE
• TYPE (payroll), DIMENSION(10) costCenter

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Component Selector

• Components of derived data types can be used
  independently just as any other data type.
• The component is specified by a component
  selector that consists of the name of the
  variable followed by the then the component
  name.
• Example joeage 38

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Addressing derived data arrays

• To address a component within an array of a
  derived data type, the subscript is placed after
  the array name and prior to the .
• Example costcenter(2) payrollHours 30