A. The statement goif1 = NEW cl1( ... ) is valid. It creates an instance of class cl1 and assigns its reference to the interface reference variable goif1. This is a permitted up-cast because class cl1 publicly implements the interface if1.

B. The interface reference variable goif1 has the static type if1. Therefore, it can be used to access all components defined in the interface if1, including the method m1. The syntax goif1->m1( ... ) is the correct way to call this method.

C. The class reference variable gocl1 can be used to call methods from interfaces that the class cl1 implements. To avoid ambiguity, the interface name must be specified using the interface component selector (~). Thus, gocl1->if1~m1( ... ) is the correct syntax.

D. To call an interface method via a class reference, the interface name must be used as a prefix (if1~m1), unless an alias has been defined. No alias is defined in the code.

E. An interface reference variable (goif1) can only access components defined within that interface. The method m2 is a component of the class cl1 and is not part of the interface if1.

1. SAP Help Portal

ABAP Keyword Documentation

NEW - Instance Operator:

Regarding option A: "The static type of lhs [the left side

goif1] must be more general than or identical to the data type type [cl1] specified after NEW or the data type of .... In other words

the reference in type must be able to be assigned to lhs in an up cast." Since cl1 implements if1

this condition is met.

2. SAP Help Portal

ABAP Keyword Documentation

Polymorphism - Using Interface Reference Variables:

Regarding option B: "An interface reference variable iref allows a user to access the interface components of the object to which it points." This confirms that goif1 can access method m1.

Regarding option E: This same principle confirms that goif1 cannot access class-specific components like m2

as they are not part of the interface's definition.

3. SAP Help Portal

ABAP Keyword Documentation

CALL METHOD - Statically:

Regarding option C and D: "If meth is an interface method

the name of the interface intf and the interface component selector (~) must be specified before the name of the method meth." This validates the syntax in option C and invalidates the direct call in option D (in the absence of an alias).