Lecture 7 - OOP Foundations

Question 1

What is a publicized service made available to others?

Answer 1

Interface

Question 2

TF: The implementation of an interface is usually visible to user of the interface

Answer 2

False. Implementation generally hidden

Question 3

At what time is a collection of classes organized into packages (hint: static point of view)?

Answer 3

At compile-time

Question 4

At what time is a program a collaborating community of objects that uses class features (data, method)?

Answer 4

At runtime

Question 5

What are Basic (primitive) types?

Answer 5

• int
• long
• double
• void
• boolean

Question 6

What are Reference types?

Answer 6

• Class
• Interface
• Array

Question 7

TF: A stack cannot hold the value of a primitive type

Answer 7

False. It can

Question 8

TF: A stack can hold the value NULL

Answer 8

True

Question 9

TF: A stack cannot hold a reference (pointer) to an object allocated in Heap

Answer 9

False. It can

Question 10

TF: A stack can hold Objects

Answer 10

False. It cannot

Question 11

TF: A heap can only hold objects that were created via “new”

Answer 11

True

Question 12

What are the two things defined by a class?

Answer 12

• A type
• An implementation

Question 13

What is defined by an interface?

Answer 13

• A type
  (without an implementation)
  Note: interface has no logic (logic defined by class implementing interface)

Question 14

What are the two types an expression can?

Answer 14

• Compile-time (static) type
• Runtime (dynamic) type