Introduction to Derived Types

Abstract

The aim of this chapter is to introduce the concepts and ideas involved in using the facilities offered in Fortran 90 for the construction and use of user defined types: The way in which we define our own types. The way in which we declare variables to be of a user defined type. The way in which we manipulate variables of our own types. The way in which we can nest types within types.

Russell’s theory of types leads to certain complexities in the foundations of mathematics… Its interesting features for our purposes are that types are used to prevent certain erroneous expressions from being used in logical and mathematical formulae; and that a check against violation of type constraints can be made purely by scanning the text, without any knowledge of the value which a particular symbol might happen to have.

C.A.R. Hoare, Structured Programming