FORTRAN Reference Manual

Statements
FORTRAN Reference Manual—528615-001
7-106
SUBROUTINE Statement
SUBROUTINE Statement
The SUBROUTINE statement is the first statement of a subroutine.
name
is the symbolic name of the subroutine. It has the scope of an executable program.
dummy
is a variable name, an array name, a RECORD name, a dummy procedure name
or an asterisk, which corresponds to an alternate return specifier in a CALL
statement.
Considerations
•
A subroutine must begin with a SUBROUTINE statement and end with an END
statement.
•
A subroutine can include one or more ENTRY statements and one or more
RETURN statements.
•
The name of dummy has the scope of the subroutine. Do not declare it in an
EQUIVALENCE, PARAMETER, DATA, INTRINSIC, SAVE, or COMMON statement
(except as a common block name) within the program unit.
•
The subroutine name has the scope of an executable program and must be
different from any other external name.
•
The subroutine name must not be the same as any common block name declared
anywhere in the executable program.
•
For additional information about subroutines, see Section 4, Program Units.
Example
SUBROUTINE namelength (name, length)
CHARACTER name*(*)
length = LEN(name)
IF (length .GT. 80) THEN
PRINT *, 'YOUR ENTRY IS TOO LONG!'
END IF
END
SUBROUTINE name [ ( [ dummy [, dummy ]... ] ) ]