Transfers control to an external subroutine.
||Name of the external subroutine to call.
statement can be used to call an external subroutine. The external subroutine must have been compiled and cataloged. No parameters can be passed using ENTER
; use CALL
if you need to pass parameters to a subroutine. When ENTER
is used to call an external subroutine, the RETURN
statement within the external subroutine does not return control to calling program; use CALL
if you need to return following a subroutine call.
calls the external subroutine without increasing the stack level. This can be useful when issuing a large number of calls without returning. Because ENTER
is not increasing the stack level, a <FRAMESTACK> error cannot occur.
You can use name
to specify the external subroutine either directly or indirectly:
argument can specify the exact name under which the subroutine was cataloged.
argument can specify the name of a variable that contains the name of the subroutine. A variable of this type is prefaced with the @ symbol. A variable name can be a local variable, or an element of an array.
You can also use the COMMON
statement to make specified variables available to all external subroutines.
ENTER, CALL, GOSUB, and SUBR
statement is used to call an external subroutine with no parameter passing or return, and without increasing the stack level. The CALL
statement is used to call an external subroutine with parameter passing and returning. CALL
increases the stack level.
statement is used to call an internal subroutine. The SUBR
function is used to call an external subroutine that returns a value.
The following example uses ENTER
to call an external subroutine:
PRINT x ! Returns "Burma"
PRINT x ! Does not execute
PRINT "An error occurred"