Open Watcom FORTRAN 77 Language Reference

FORTRAN Statements
2.45 FUNCTION Statement
A FUNCTION statement is used to define the start of a function subprogram. There are two forms of the
FUNCTION function statement. The second form is a Open Watcom FORTRAN 77 extension.
2.45.1 Standard FUNCTION Statement
[type] FUNCTION fun ( [d [, d] ...] )
where:
type
fun
d
len
is one of LOGICAL, INTEGER, REAL, DOUBLE PRECISION, COMPLEX or CHARACTER
[*len].
is a symbolic name of a function subprogram.
is a variable name, array name, or a dummy procedure name. d is called a dummy argument.
is called the length specification and is the length (number of characters) of the result of the
character function. It has one of the following forms:
(1) An unsigned positive integer constant.
(2) A positive integer constant expression enclosed in parentheses.
(3) An asterisk in parentheses, (*).
Example:
PRINT *, TMAX3( -1.0, 12.0, 5.0 )
END
FUNCTION TMAX3( ARGA, ARGB, ARGC )
TMAX3 = ARGA
IF( ARGB .GT. TMAX3 ) TMAX3 = ARGB
IF( ARGC .GT. TMAX3 ) TMAX3 = ARGC
END
In the above example, the function TMAX3 is defined to find the maximum of three real variables.
Notes:
1. No dummy arguments need be specified in the FUNCTION statement. However, the parentheses
() are mandatory.
For more information, see the chapter entitled "Functions and Subroutines" on page 243.
FUNCTION Statement 77