Deck 1: Object-Oriented Programming and Class Hierarchies

Question 1

Each class that implements an interface must provide the complete definition of all methods declared in the interface.

Answer 1

True

Question 2

One way to make code reusable is to ____________________ or combine data elements together with methods that operate on that data in a separate program module.

Answer 2

encapsulate

Question 3

The combination of data together with its methods is called a(n) ____________________ data type.

Answer 3

abstract

Question 4

A Java ____________________ specifies the names, parameters, and return values of the ADT methods without specifying how the methods perform their operations or how the data is internally represented.

Question 5

Method descriptions in an interface are called method ____________________.

Question 6

The Javadoc program for Java documentation focuses on text that is enclosed with the delimeters ____________________.

Question 7

A(n) ____ is a model of a physical entity or activity.

A) abstraction
B) interface
C) contract
D) use case

Question 8

A Java interface is a(n) ____ between the interface designer and the programmer who codes a class that implements the interface.

A) precondition
B) postcondition
C) message
D) contract

Question 9

A major reason for the popularity of object-oriented programming is that it enables programmers to reuse previously written code saved as classes.

Question 10

An object that is a RuntimeException is an Exception. The converse is also true.

Question 11

The has-a relationship between classes means that one class is a subclass of the other.

Question 12

The is-a relationship between classes means that one class has the second class as an attribute.

Question 13

The superclass of all Java classes is ____________________.

Question 14

The ____________________ call in a class constructor invokes the superclass's constructor that has the corresponding argumentList.

Question 15

Java automatically applies the ____________________ method to an object referenced in a String expression.

Question 16

Having multiple methods with the same name but different signatures in a class is called ____________________.

Question 17

A(n) ____________________ class is used to store a primitive-type value in an object type.

Question 18

You should always override the ____________________ method if you want to represent an object's state.

Question 19

In UML class diagrams, the ____ sign next to the method names indicate that the methods are public.

A) @
B) *
C) +
D) -

Question 20

If no constructors are defined for a class, the ____ constructor for that class will be provided by default.

A) private
B) super
C) public
D) no-parameter

Question 21

A data field (or method) with ____ visibility can be accessed in either the class defining it, in any subclass of that class, or any class in the same package.

A) private
B) protected
C) public
D) instanceof

Question 22

The call to ____ invokes the constructor for the current class whose parameter list matches the argument list.

A) super()
B) super
C) this()
D) abstract

Question 23

Which of the following statements is correct?

A) is-a and has-a relationships cannot be combined.
B) An abstract class can be instantiated.
C) An abstract class cannot declare abstract methods.
D) In Java, a variable of a superclass type can reference an object of a subclass type.

Question 24

Which of the following statements is correct?

A) Interfaces can define instance variables and methods.
B) Abstract classes can define constants.
C) Interfaces can extend another class.
D) Instances of abstract classes can be created.

Question 25

Which of the following methods of java.lang.Object compares an object to its argument?

A) boolean equals(Object obj)
B) int hashCode()
C) Object clone()
D) String toString()

Question 26

The nextInt method will throw a(n) if an integer choice is
not entered.

Question 27

ArrayIndexOutOfBoundsException is thrown by the JVM when an index value used to access an element in an array is less than zero or greater than or equal to the array's length.

Question 28

A ____________________ is thrown when the token returned by a Scanner next... method does not match the pattern for the expected data type.

A) ArithmeticException
B) IllegalArgumentException
C) InputMismatchException
D) NumberFormatException

Question 29

____________________ errors are mistakes in your use of the grammar of the Java language.

Question 30

____________________ errors occur during program execution .

Question 31

The ____________________ is thrown when a program attempts to convert a non-numeric string to a numeric value.

Question 32

The class ____________________ is the superclass of all exceptions.

Question 33

Which of the following would cause an ArrayIndexOutOfBounds error?

A) public boolean setElementOfX(int index, int val) {
if(index >= 0 && index < x.length) {
x[index] = val;
return true;
} else {
return false;
}
}
B) public static void main(Strin[] args) {
String inputFileName;

if (args.length > 0)
inputFileName = args[0];
else
inputFileName = "Phone.dat";
}
C) for (int i = 0; i
x[i] = i + i;
D) for (int i = 0; i <= x.length; i++)
x[i] = i * i;

Question 34

A(n) ____ is an error that is normally not due to programmer error and is beyond the control of the programmer.

A) checked exception
B) bug
C) syntax error
D) unchecked exception

Question 35

Which of the following statements is correct?

A) If a checked exception is likely to be caught in a higher-level method, declare that it can occur using a catch clause.
B) If an exception is recoverable in the current method, handle the exception in the current method.
C) If an unchecked exception is is likely to be caught in a higher-level method, use a @catch tag to document this fact in the Javadoc comment for the method.
D) If an unchecked exception is likely to be caught in a higher-level method, declare that it can occur using a throws clause.

Question 36

The ____ represent error conditions that may occur as a result of programmer error or as a result of serious external conditions that are considered unrecoverable.

A) unchecked exceptions
B) run-time error
C) checked exceptions
D) exception

Question 37

Exception classes that are subclasses of ____ are unchecked.

A) EOFException
B) FileNotFoundException
C) IOException
D) RuntimeException

Question 38

Which of the following is a RuntimeException?

A) AssertionErorr
B) FileNotFoundException
C) IllegalArgumentException
D) UnknownError

Question 39

Classes that are not part of a package may access only ________________ members of classes in the package.

Question 40

____________________ visibility is for members of a class that should not be accessible to anyone but the class, not even classes that extend it.

Question 41

Which of the following is considered a visibility modifier in Java?

A) private
B) Inherit
C) Superclass
D) String