ABSTRACT
A user-defined data type is a data structure created by the user consisting of elementary elements of standard types such as integer, real, logical, complex and character variables. The variables declared as user-defined data type can be accessed as a whole, or the elementary items may be manipulated separately. Initialization of user-defined data type variables can be done in two different ways. One is to initialize at the prototype level and the other at the variable level. The implicit declaration ensures that any variable that starts with either d or e in the program unit is of user-defined data type donor. Statement equivalence works on the assumption that storage is arranged in sequence. Naturally, sequence must be used if equivalence with derived types is desired.
