Cop3252 Midterm

Front 1

________ is a graphical language that allows people who design software systems to use an industry standard notation to represent them.

Back 1

The Unified Modeling Language

Front 2

What is the difference between a float and a double?

Back 2

Double variables store numbers with larger magnitude and finer detail.

Front 3

Which command executes the Java class file Welcome.class?

Back 3

java Welcome

Front 4

Which of the following is not one of the six logical units of a computer?

Back 4

Printer

Front 5

Which of the following is not a control structure:

Back 5

Declaration structure.

Front 6

All import declarations must be placed

Back 6

before the class declaration.

Front 7

Which of the following is not a Java primitive type?

Back 7

real

Front 8

Every Java application is composed of at least one:

Back 8

public class declaration

Front 9

Which of the following statements is false?

Back 9

Information in the memory unit is persistent—it is retained when the computer's power is turned off.

Front 10

What is output by the following Java code segment?
int temp = 180;

while ( temp != 80 )
{
if ( temp > 90 )
{
System.out.print( "This porridge is too hot! " );

// cool down
temp = temp – ( temp > 150 ? 100 : 20 );
} // end if
else
{
if ( temp < 70 )
{
System.out.print(
"This porridge is too cold! ");

// warm up
temp = temp + (temp < 50 ? 30 : 20);
} // end if
} // end else
} // end while

if ( temp == 80 )
System.out.println( "This porridge is just right!" );

Back 10

This porridge is too hot! This porridge is just right!

Front 11

Which command compiles the Java source code file Welcome.java?

Back 11

javac Welcome.java

Front 12

Which class provides prebuilt dialog boxes that enable programs to display windows containing messages (such windows are called message dialogs)?

Back 12

JOptionPane

Front 13

Attributes of a class are also known as:

Back 13

Fields

Front 14

Which of the following is not one of the three general types of computer languages?

Back 14

Spoken languages.

Front 15

What is the default value of a reference?

Back 15

null

Front 16

What does the expression x %= 10 do?

Back 16

Divides x by 10 and stores the remainder in x.

Front 17

Which of the following does not contain a syntax error?

Back 17

System.out.println( "Hello world!" );

Front 18

Which statement is true?

Back 18

Syntax errors are caught by the compiler. Logic errors have effects at execution time.

Front 19

What is the result value of c at the end of the following code segment?
int c = 8;
c++;
++c;
c %= 5;

Back 19

0

Front 20

What is output by the following Java code segment?
int temp = 180;

if ( temp > 90 )
{
System.out.println( "This porridge is too hot." );

// cool down
temp = temp – ( temp > 150 ? 100 : 20 );
} // end if
else
{
if ( temp < 70 )
{
System.out.println("This porridge is too cold.");

// warm up
temp = temp + (temp < 50 ? 30 : 20);
} // end if
} // end else

if ( temp == 80 )
System.out.println( "This porridge is just right!" );

Back 20

None of the above.

Front 21

Which of the following statements about the break statement is false?

Back 21

The break statement, when executed in a while, for or do…while, skips the remaining statements in the loop body and proceeds with the next iteration of the loop.

Front 22

Consider the following two Java code segments:

Segment 1

int i = 0;
while ( i < 20 )
{
i++;
System.out.println( i );
}

Segment 2

for ( int i = 0; i <= 20; i++ )
{
System.out.println( i );
}

Back 22

Both (a) and (b) are true.

Front 23

Which of the following will count down from 10 to 1 correctly?

Back 23

for ( int j = 10; j >= 1; j-- )

Front 24

Which of the following statements about the continue statement is true?

Back 24

A continue statement proceeds with the next iteration of the immediately enclosing while, for, do…while statement.

Front 25

Which of the following statements about a do…while repetition statement is true?

Back 25

The body of a do…while loop is always executed at least once.

Front 26

To exit out of a loop completely, and resume the flow of control at the next line in the method, use _______.

Back 26

A break statement

Front 27

Consider the code segment below.

if ( gender == 1 )
{
if ( age >= 65 )
++seniorFemales;
} // end if

This segment is equivalent to which of the following?

Back 27

if ( gender == 1 && age >= 65 )
++seniorFemales;

Front 28

For the code segment below:

switch( q )
{
case 1:
System.out.println( "apple" );
break;
case 2:
System.out.println( "orange" );
break;
case 3:
System.out.println( "banana" );
break;
case 4:
System.out.println( "pear" );
case 5:
System.out.println( "grapes" );
default:
System.out.println( "kiwi" );
} // end switch

Which of the following values for q will result in kiwi being included in the output?

Back 28

Anything greater than or equal to 4.

Front 29

Suppose variable gender is MALE and age equals 60, how is the expression
( gender == FEMALE ) && ( age >= 65 )
evaluated?

Back 29

The condition ( gender == FEMALE ) is evaluated first and the evaluation stops immediately.

Front 30

The control variable of a counter-controlled loop should be declared as ________to prevent errors.

Back 30

int

Front 31

Which statement creates a random value from the sequence 2, 5, 8, 11 and 14. Suppose randomNumbers is a Random object.

Back 31

2 + 3 * randomNumbers.nextInt( 5 );

Front 32

In a class containing methods with the same name, the methods are distinguished by:

Back 32

(a) and (b).

Number of arguments.

Types of arguments.

Front 33

Suppose method1 is declared as

void method1 ( int a, float b )

Back 33

void method1 ( float a, int b )

Front 34

Declaring main as ________ allows the JVM to invoke main without creating an instance of the class.

Back 34

static.

Front 35

To declare a method as static, place the keyword static before ________ in the method’s declaration.

Back 35

the return type.

Front 36

A well-designed method

Back 36

performs a single, well-defined task

Front 37

An overloaded method is one that

Back 37

has the same name as another method, but different parameters (by number, types or order of the types).

Front 38

Consider the following Java statements:

int x = 9;
double y = 5.3;
result = calculateValue( x, y );

Back 38

x and y are parameters.

Front 39

Which statement is not true.

Back 39

The Java API consists of import declarations.

Front 40

Stacks are known as ________ data structures.

Back 40

LIFO

Front 41

A programmer must do the following before using an array:

Back 41

declare then create the array.

Front 42

Which statement correctly passes the array items to method takeArray? Array items contains 10 elements.

Back 42

takeArray( items )

Front 43

What do the following statements do?

double[] array;
array = new double[ 14 ];

Back 43

Create a double array containing 14 elements

Front 44

In this question, assume a class, Book, has been defined. Which set of statements creates an array of Book objects?

Back 44

Book[] books;
books = new Book[ numberElements ];

Front 45

Which method call converts the value in variable stringVariable to an integer?

Back 45

Integer.parseInt( stringVariable ).

Front 46

Consider the array:

s[ 0 ] = 7
s[ 1 ] = 0
s[ 2 ] = -12
s[ 3 ] = 9
s[ 4 ] = 10
s[ 5 ] = 3
s[ 6 ] = 6

The value of s[ s[ 6 ] - s[ 5 ] ] is:

Back 46

9

Front 47

Arrays are:

Back 47

fixed-length entities.

Front 48

Attempting to access an array element out of the bounds of an array, causes a(n)

Back 48

ArrayIndexOutOfBoundsException.

Front 49

Consider the program below:

public class Test
{
public static void main( String[] args )
{
int[] a;
a = new int[ 10 ];

for ( int i = 0; i < a.length; i++ )
a[ i ] = i + 2;
int result = 0;
for ( int i = 0; i < a.length; i++ )
result += a[ i ];
System.out.printf( "Result is: %d\n", result );
} // end main
} // end class Test

The output of this program will be:

Back 49

Result is: 65.

Front 50

The preferred way to traverse a two-dimensional array is to use

Back 50

two nested for statements.

Front 51

Which of the following should usually be private?

Back 51

Variables (or fields).

Front 52

Having a this reference allows:

Back 52

A) a method to refer explicitly to the instance variables and other methods of the object on which the method was called
B) a method to refer implicitly to the instance variables and other methods of the object on which the method was called
C) an object to reference itself

All of the above.

Front 53

A class within a package must be declared public if

Back 53

It will be used by classes that are not in the same package.

Front 54

The import declaration import *; ________.

Back 54

causes a compilation error.

Front 55

When should a program explicitly use the this reference?

Back 55

Accessing a field that is shadowed by a local variable.

Front 56

When no access modifier is specified for a method or variable, the method or variable:

Back 56

Has package access.

Front 57

Static class variables:

Back 57

are shared by all objects of a class.

Front 58

Which of the following is false?

Back 58

Objects are marked for garbage collection by method finalize.

Front 59

Instance variables declared final do not or cannot:

Back 59

Be modified.

Front 60

A package is:

Back 60

a.A directory structure used to organize classes and interfaces.

b.A mechanism for software reuse.

c.A group of related classes and interfaces

ALL OF THE ABOVE!

Front 61

Failure to prefix the superclass method name with the keyword super and a dot (.) separator when referencing the superclass’s method causes ________.

Back 61

infinite recursion

Front 62

An advantage of inheritance is that:

Back 62

Objects of a subclass can be treated like objects of their superclass.

Front 63

Superclass methods with this level of access cannot be called from subclasses.

Back 63

private

Front 64

Overriding a method differs from overloading a method because:

Back 64

Overridden methods have the same signature.

Front 65

Using the protected keyword gives a member:

Back 65

package access

Front 66

Which superclass members are inherited by all subclasses of that superclass?

Back 66

protected instance variables and methods

Front 67

Every class in Java, except ________, extends an existing class.

Back 67

Object

Front 68

Which of the following keywords allows a subclass to access a superclass method even when the subclass has overridden the superclass method?

Back 68

super

Front 69

The default implementation of method clone of Object performs a ________.

Back 69

shallow copy

Front 70

When a subclass constructor calls its superclass constructor, what happens if the superclass’s constructor does not assign a value to an instance variable?

Back 70

The program compiles and runs because the instance variables are initialized to their default values

Front 71

Which of the following is a Scanner method?

Back 71

nextLine

Front 72

Which of the following is not a Java keyword?

Back 72

next

Front 73

Which of the following is a valid fully qualified name?

Back 73

java.util.Scanner

Front 74

Which of the following statements is true?

Back 74

Compilers translate high-level language programs into machine language programs.

Front 75

A(n) ________ enables a program to read data from the user.

Back 75

Scanner

Front 76

Which statement is true?

Back 76

Syntax errors are caught by the compiler. Logic errors have effects at execution time.

Front 77

________ models software in terms similar to those that people use to describe real-world objects.

Back 77

Object-oriented design