DIMENSION attribute

Standard: (F77) F90 F95 F2003 F2008 Example program

＜Syntax＞

type, DIMENSION ( array-spec ) [ , attr-spec ]... :: decl-list

DIMENSION [ :: ] name ( array-spec ) [ , name ( array-spec ) ]...

array-spec	::=	assumed-shape
	\|	assumed-size
	\|	deferred-shape
	\|	explicit-shape
	\|	implied-shape

assumed-shape ::= a-bound [ , a-bound ]...
a-bound ::= [ expression ] :

assumed-size ::= [ e-bound , ]... asize-bound
asize-bound ::= [ expression : ] *

explicit-shape ::= e-bound [ , e-bound ]...
e-bound ::= [ expression : ] expression

deferred-shape ::= d-bound [ , d-bound ]...
d-bound ::= :

implied-shape ::= i-bound [ , i-bound ]...
i-bound ::= [ expression : ] *

＜Semantics＞

The DIMENSION attribute declares arrays. An assumed-shape or assumed-size array must be a dummy argument, a deferred-shape array must be a pointer or allocatable array, and an implied-shape array must be a named constant (the shape is implied by the shape of the defining expression for the constant). If a lower bound expression is omitted, that lower bound will have the value one.

The maximum rank (number of dimensions) of an array is 7 prior to Fortran 2008, and 15 from Fortran 2008 onwards. Release 6.0 of the NAG Fortran Compiler supports a maximum rank of 31.

The DIMENSION attribute can also be specified by putting an array-spec in parentheses after the entity name in a type declaration or component definition statement; this overrides any DIMENSION clause that might be present.