Article
Interface Parameters in Methods
Interface parameters in methods are input parameters ( IMPORTING ,
CHANGING parameters) and output parameters ( EXPORTING ,
CHANGING , RETURNING parameters). In declarations with the
statements
METHODS
CLASS-METHODS
EVENTS
CLASS-EVENTS
the following attributes are determined:
Passing parameters by reference or by value
With the exception of the return value ( RETURNING parameters),
parameters can be passed both by value or reference. Passing by
reference is standard with methods. If only a name p is specified
in the parameter declaration, the parameter is passed implicitly as a
reference. If a VALUE(p) is specified instead, then the
parameter is passed as a value. The return value may only be passed as a
value. Passing by reference can also be explicitly specified with other
parameters using
REFERENCE(p) . An IMPORTING parameter transferred by
reference, cannot be changed in the method.
Typing parameters
All parameters must be typed during
declaration using the addition TYPE or the addition
LIKE . The following entries are allowed after TYPE
as parameter types:
Optional parameters
All input parameters ( IMPORTING , CHANGING parameters) can
be defined in the declaration as optional parameters using the additions
OPTIONAL or DEFAULT . These parameters must not necessarily
be transfered when the method is called. With the addition OPTIONAL
your parameter remains initialized according to type, while the
addition DEFAULT allows you to enter a start value.
Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved