AP CS - Java - gonimbus

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This quiz randomly generates 20 questions as asked in AP Computer Science A (AP CSA) - Programming in Java.

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AP Computer Science A (AP CSA) - Programming in Java

This quiz randomly generates 20 questions (in 30 mins) as asked in AP Computer Science A (AP CSA) - Programming in Java.

1 / 20

What is the output?

A B

B A

A Null Pointer Exception is thrown at runtime.

A 0 B 1

2 / 20

Question

The method reduce() is not a public method because

methods whose return type is void cannot be public.

methods that change this cannot be public

the reduce() method is not intended for use by clients of the Rational class.

the reduce() method is intended for use only by clients of the Rational class.

the reduce() method uses only the private data fields of the Rational class.

3 / 20

A programmer is designing a program to catalog all books in a library. He plans to have a Book class that stores features of each book: author, title, isOnShelf and so on, with operations like getAuthor, getTitle, getShelfInfo, and
setShelfInfo. Another class, LibraryList, will store an array of Book objects. The LibraryList class will include operations such as listAllBooks, addBook, removeBook, and searchForBook. The programmer plans to implement and test the Book class first, before implementing the LibraryList class. The programmer's plan to write the Book class first is an example of

top-down development.

bottom-up development.

procedural abstraction.

information hiding.

a driver program.

4 / 20

Refer to the following code fragment:

double answer = (double) 13 / 5;

double answer = 13 / (double) 5;

double answer = 13.0 / 5;

double answer = 13 / 5.0;

double answer = (double) (13 / 5);

6 / 20

What is the output?

1:2:3:4:5:

1:2:3:

Compilation fails

An ArrayOutOfBoundsException is thrown at runtime

Four words become HiHowAreYou, since its length is more than 4, nothing will be removed and HiHowAreYou removed will be printed.

7 / 20

What is the output?

Compilation fails.

The program compiles, but it prints nothing.

HiHowAreYou removed

An UnsupportedOperationException is thrown at runtime.

9 / 20

Question

r = a.plus(r);

a = r. plus (new Rational (n));

r = r.plus(r);

a = n. plus(r);

r = r. plus (new Rational(n));

10 / 20

What is the output?

C B A

A B C

Compilation fails at line n1 and line n2

11 / 20

Question

Which of the following is a false statement about the methods?

equals, lessThan, and toString are all accessor methods.

increment is a mutator method.

Time() is the default constructor.

The Time class has two constructors.

There are no static methods in this class.

12 / 20

Question

Rational r1 = new Rational();

Rational r2 = r1;

Rational r3 = new Rational (2,-3);

Rational r4 = new Rational (3.5);

Rational r5 = new Rational (10);

13 / 20

What is the output?

An exception is thrown at runtime.

07-31-2014

2014-07-31

2014-09-30

14 / 20

The boolean expression !A && B || C is equivalent to

!A && (B II C)

((!A) && B) II C

(!A) && (B II C)

!(A && B) II C

!(A && B II C)

15 / 20

What is the output?

Compilation fails at line n2.

Compilation fails at line n1

20:20

10:20

17 / 20

For the sample code:

Consider this description of the Deck constructor:

if (i / 13 == 1) myDeck [i / 13] = new Card("hearts", i % 13);

i f (i >= 13 && i <= 25) myDeck [i % 13] = new Card("hearts", i % 13);

i f ( i / 13 == 1) myDeck [i] = new Card("hearts", i % 13);

i f (i >= 13 && i <= 25) myDeck [i] = new Card("hearts", i / 13);

i f (i / 13 == 1) myDeck [i % 13] = new Card("hearts", i % 13);

18 / 20

Question

Round-off eror was caused by calculations with floating-point numbers.

Type boolean was not recognized by an obsolete version of Java.

An overflow error was caused by entering numbers that were too large.

c and d should have been cast to integers before testing for equality.

Bad test data were selected.

19 / 20

What is the output?

1 2 3 0 01 2 3 0 0

An Exception is thrown at run time.

1 2 3 0 01 2 3

1 2 31 2 3

20 / 20

Which code fragment, when inserted at line 6, enables the code to print true?

String str2 = str1;

String str2 = new String(str1);

String str2 = sb1.toString();

String str2 = "Duke";

Your score is