Open Watcom FORTRAN 77 Language Reference

FORTRAN Statements
2.79 SUBROUTINE Statement
SUBROUTINE sub [( [d [, d] ...] )]
where:
sub
d
is a symbolic name of a subroutine subprogram.
is a variable name, array name, dummy procedure name or an asterisk (*). d is called a dummy
argument.
A SUBROUTINE statement is used to define the start of a subroutine subprogram.
Example:
CALL TMAX3( -1.0, 12.0, 5.0 )
END
SUBROUTINE TMAX3( ARGA, ARGB, ARGC )
THEMAX = ARGA
IF( ARGB .GT. THEMAX ) THEMAX = ARGB
IF( ARGC .GT. THEMAX ) THEMAX = ARGC
PRINT *, THEMAX
END
In the above example, the subroutine TMAX3 is defined to find and print out the maximum value of three
real variables.
Notes:
1. No dummy arguments need be specified in the SUBROUTINE statement. If such is the case, the
parentheses () are optional.
For more information, see the chapter entitled "Functions and Subroutines" on page 243.
SUBROUTINE Statement 141