IBM SC34-5764-01 User Manual

Page 81

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instruction(s)
EXIT

instruction(s)

instruction(s)
RETURN

z=func1(arg1, arg2)

Both subroutines and functions can be internal (designated by a label) or external (designated by the
subroutine or function in the REXX File System/VSE Librarian sublibrary member name). The two
preceding examples illustrate an internal subroutine named sub1 and an internal function named func1.

IMPORTANT NOTE

Because internal subroutines and functions generally appear after the main part of the program,
when you have an internal subroutine or function, it is important to end the main part of the program
with the EXIT instruction.

The following illustrates an external subroutine named sub2.

instruction(s)


...

sub2:

instruction(s)
RETURN

instruction(s)
CALL sub2

MAIN

The following illustrates an external function named func2.

Writing Subroutines and Functions

Chapter 6. Writing Subroutines and Functions

59

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