Question 1

Given the declaration Circle[] x = new Circle[10], which of the following statement is most accurate.

Accepted Answer

A)  x contains an array of ten int values. 
B)  x contains a reference to an array and each element in the array can hold a Circle object. 
C)  x contains an array of ten objects of the Circle type. 
D)  x contains a reference to an array and each element in the array can hold a reference to a Circle object. D

Question 2

Accepted Answer

A)  0 
B)  2 
C)  -2 
D)  -1 
E)  1 C

Question 3

_________ returns the last character in a StringBuffer variable named strBuf?

Accepted Answer

A)  strBuf.charAt(strBuf.capacity() - 1) 
B)  StringBuffer.charAt(strBuf.capacity () - 1) 
C)  StringBuffer.charAt(strBuf.length ()$ -1) $ 
D)  strBuf.charAt(strBuf.length() - 1) D

Question 4

What is the printout for the third print statement in the main method?

Accepted Answer

A)  j is 3 
B)  j is 2 
C)  j is 1 
D)  j is 0

Question 5

When invoking a method with an object argument, ___________ is passed.

Accepted Answer

A)  a copy of the object 
B)  the object is copied, then the reference of the copied object 
C)  the reference of the object 
D)  the contents of the object

Question 6

Analyze the following code:

Accepted Answer

A)  The program has compile errors because the variable radius is not initialized. 
B)  The program compiles and runs fine. 
C)  The program has no compile errors but will get a runtime error because radius is not initialized. 
D)  The program has a compile error because a constant PI is defined inside a method.

Question 7

Analyze the following code.

Accepted Answer

A)  The program has a runtime error because s is not initialized, but it is referenced in the println statement. 
B)  The program has a compile error because s is not initialized, but it is referenced in the println statement. 
C)  The program has a runtime error because s is null in the println statement. 
D)  The program compiles and runs fine.

Question 8

________ is invoked to create an object.

Accepted Answer

A)  The main method 
B)  A method with a return type 
C)  A method with the void return type 
D)  A constructor

Question 9

Given the declaration Circle x = new Circle(), which of the following statement is most accurate.

Accepted Answer

A)  x contains an object of the Circle type. 
B)  You can assign an int value to x. 
C)  x contains a reference to a Circle object. 
D)  x contains an int value.

Question 10

Analyze the following code:

Accepted Answer

A)  The program has a compile error because you cannot assign radius to radius. 
B)  The program will compile, but you cannot create an object of Circle with a specified radius. The object will always have radius 0. 
C)  The program does not compile because Circle does not have a default constructor. 
D)  The program has a compilation error because it does not have a main method.

Question 11

What is the value of myCount.count displayed?

Accepted Answer

A)  99 
B)  101 
C)  100 
D)  98

Question 12

Analyze the following code:

Accepted Answer

A)  The program compiles and runs fine. 
B)  The program has no compile errors but will get a runtime error because radius is not initialized. 
C)  The program has compile errors because the variable radius is not initialized. 
D)  The program has a compile error because a constant PI is defined inside a method.

Question 13

Analyze the following code:

Accepted Answer

A)  The program compiles and runs fine. 
B)  The variable t is private and therefore cannot be accessed in the main method. 
C)  The variable x is not initialized and therefore causes errors. 
D)  t is non-static and it cannot be referenced in a static context in the main method. 
E)  The variable t is not initialized and therefore causes errors.

Question 14

What is the output of the following program?

Accepted Answer

A)  76543211234567 
B)  76543217654321 
C)  12345671234567 
D)  12345677654321

Question 15

Analyze the following code.

Accepted Answer

A)  The program has a compile error because x has not been initialized. 
B)  The program has a compile error because test is not initialized. 
C)  The program has a runtime NullPointerException because test is null while executing test.x. 
D)  The program has a compile error because you cannot create an object from the class that defines the object. 
E)  The program has a compile error because Test does not have a default constructor.

Exam 8: Objects and Classes

Given the declaration Circle[] x = new Circle[10], which of the following statement is most accurate.

_________ returns the last character in a StringBuffer variable named strBuf?

What is the printout for the third print statement in the main method?

When invoking a method with an object argument, ___________ is passed.

Analyze the following code:

Analyze the following code.

________ is invoked to create an object.

Given the declaration Circle x = new Circle() , which of the following statement is most accurate.

Analyze the following code:

What is the value of myCount.count displayed?

Analyze the following code:

Analyze the following code:

What is the output of the following program?

Analyze the following code.