TAW_12 Chapter 4, Interfaces and casting

Question 1

What section do all interface components belong too

Answer 1

Public

Question 2

True or false, interfaces closely resemble super classes

Answer 2

True

Question 3

What do interfaces primarily serve to define?

Answer 3

Uniform interface protocols

Question 4

In UML, how are interfaces noted?

Answer 4

<> and a dotted line

Question 5

How are interface components addressed?

Answer 5

~
Full access would be
->~

Question 6

Aliases can be defined for a complete ineterface?

Answer 6

No, only by component?

Question 7

Because interfaces must be implemented in the public section, all aliases must also be implemented at the public level?

Answer 7

No, you can define an alias in protected or private

Question 8

How can an alias be defined?

Answer 8

ALIASES new_name

FOR ~

Question 9

Class A uses interface B. Can I upcast an object of type A to a ref variable of class B?

Answer 9

Yes, that’s the whole point. At that you no longer need to use the instance syntax of ~

Question 10

Describe using n interface reference?

Answer 10

DATA: lo_part type ref to if_part
Loop at some_table into lo_part. “populates the ref
lo_part->display_name( ). “lo_part is just a template

Question 11

What is the main strength of interafces?

Answer 11

Poymorphism

Question 12

What are the two downcast operators?

Answer 12

TARGET ?= SOURCE
or
MOVE SOURCE ?TO TARGET

Question 13

To prevent casting errors, what catch should be used in the try block?

Answer 13

cx_sy_move_cast_error

RTTI Class services can also be used

Question 14

What happens if I extend a interface with a new method?

Answer 14

All classes using the interface must implement the new method

Question 15

Can an interface include other interfaces?

Answer 15

Yes