What is the name of the Java concept that uses access modifiers to protect variables and hide them within a class?

1. A. Encapsulation
2. B. Inheritance
3. C. Abstraction
4. D. Instantiation
5. E. Polymorphism

Correct Answer: A
Using the private modifier is the main way that an object encapsulates itself and hide data from the outside world.

Given:

What is the result?

1. A. nullRichardDonald
2. B. RichardDonald
3. C. Compilation fails.
4. D. An ArrayIndexOutOfBoundsException is thrown at runtime.
5. E. A NullPointerException is thrown at runtime.

Correct Answer: E

Which statement will empty the contents of a StringBuilder variable named sb?

1. A. s
2. B. deleteAll ();
3. C. s
4. D. delete (0, s
5. E. size () );
6. F. s
7. G. delete (0, s
8. H. length () );
9. I. s
10. J. removeAll ();

Correct Answer: C

Given the code fragment:

Which two modifications, when made independently, enable the code to print Joe:true: 100.0? (Choose two.)

1. A. Option A
2. B. Option B
3. C. Option C
4. D. Option D
5. E. Option E

Correct Answer: AC

Given the code fragment:

What is the result?

1. A. 100
2. B. 101
3. C. 102
4. D. 103
5. E. Compilation fails

Correct Answer: E