Midterm Solution

QUESTION 1

1.      A search for an item X in an array starts at the lower end of the array, and then looks for X by comparing array items to X in order of increasing subscript. Such a method is called


 
selection search

 
lower to upper search

 
sequential search

 
binary search
  

QUESTION 2

1.      Constraining a type parameter in a generic class 


 
can only be used when the generic class will be used as a superclass for other classes

 
causes programs to compile faster

 
restricts the types that can be used as type arguments

 
was added to Java in version 1.3 of the language
  

QUESTION 3

1.      In a string that contains a series of words or other items of data separated by spaces or other characters, the programming term for the spaces or other characters is


 
Delimiter

 
Separator

 
Token

 
Buffer
 

QUESTION 4

1.      In the following statement, which is the interface?

public class ClassA extends ClassB implements ClassC


 
ClassA

 
ClassB

 
ClassC

 
Cannot tell
 

QUESTION 5

1.      Look at the following statement.

import java.util.*;

This is an example of


 
a wildcard import

 
conditional import

 
unconditional import

 
an explicit import
   

QUESTION 6

1.      The scope of a private instance field is


 
Inside the class, but not inside any method

 
The instance methods of the same class

 
The method in which they are defined

 
Inside the parentheses of a method header
  

QUESTION 7

1.      Under Windows, which of the following statements will open the file InputFile.txt that is in the root directory on the C: drive?


 
FileReader freader = new FileReader("C:\InputFile.txt");

 
FileReader freader = new FileReader("/c/InputFile.txt");

 
FileReader freader = new FileReader("C:\InputFile\txt");

 
FileReader freader = new FileReader("C:\\InputFile.txt");
   

QUESTION 8

1.      What will be the value of x[1] after the following code is executed?

int[] x = { 22, 33, 44 };
arrayProcess(x);
...
public static void arrayProcess(int[] a)
{
  for(int k = 0; k < 3; k++)
  {
  a[k] = a[k] + 5;
  }
}




 
49

 
33

 
27

 
38
 

QUESTION 9

1.      What would be the results of the following code?

final int SIZE = 25;
int[] array1 = new int[SIZE];
... // Code that will put values in array1
int value = 0;
for (int a = 0; a <= array1.length; a++)
{
  value += array1[a];
}


 
value contains the sum of all the values in array1

 
value contains the lowest value in array1

 
value contains the highest value in array1

 
This would cause the program to crash
 

QUESTION 10

1.      When an array is passed to a method


 
The method has direct access to the original array

 
A reference to the array is passed

 
It is passed just as an object

 
All of the above
 

QUESTION 11

1.      Which of the following for loops is valid, given the following declaration?

String[] names = {"abc", "def", "ghi", "jkl"};


 
for (int i = 0; i < names.length; i++)
  System.out.println(names[i].length());



 
for (int i = 0; i < names.length(); i++)
  System.out.println(names[i].length);



 
for (int i = 0; i < names.length; i++)
  System.out.println(names[i].length);



 
for (int i = 0; i < names.length(); i++)
  System.out.println(names[i].length());


 

QUESTION 12

1.      Which of the following is the correct boolean expression to test for:  int x being a value between, but not including, 500 and 650, or int y not equal to 1000?


 
((x = 500 && x <= 650) && (y != 1000))

 
((x 500 && x < 650) || (y != 1000))

 
((x < 500 && x 650) || !(y == 1000))

 
((x 500 AND x < 650) OR !(y.equal(1000)))
 

QUESTION 13

1.      A protected member of a class may be directly accessed by


 
Methods of the same class

 
Methods of a subclass

 
Methods in the same package

 
All of these
   

QUESTION 14

1.      A subclass class can directly access


 
All members of the superclass class

 
Only public and private members of the superclass class

 
Only protected and private members of the superclass class

 
Only public and protected members of the superclass class
  

QUESTION 15

1.      Every class has a toString method and an equal's method inherited from the Object class.

 True

 False

  

QUESTION 16

1.      If a subclass constructor does not explicitly call a superclass constructor,


 
It must include the code necessary to initialize the superclass fields

 
The superclass fields will be set to the default values for their data types

 
Java will automatically call the superclass's default constructor immediately after the code in the subclass's constructor executes

 
Java will automatically call the superclass's default constructor just before the code in the subclass's constructor executes
   

QUESTION 17

1.      If a superclass does not have a default constructor,


 
Then a class that inherits from it, must initialize the superclass values

 
Then a class that inherits from it, must call one of the constructors that the superclass does have

 
Then a class that inherits from it, does not inherit the data member fields from the superclass

 
Then a class that inherits from it, must contain the default constructor for the superclass
  

QUESTION 18

1.      If two methods in the same class have the same name but different signatures, the second overrides the first.

 True

 False

  

QUESTION 19

1.      An exception's default error message can be retrieved using this method.


 
getMessage()

 
getErrorMessage()

 
getDefaultMessage()

 
getDefaultErrorMessage()
   

QUESTION 20

1.      If a method does not handle a possible checked exception, what must the method have?


 
A catch clause in its header

 
A try/catch clause in its header

 
A try clause in its header

 
A throws clause in its header
 

QUESTION 21

1.      In a catch statement, what does the following code do?

System.out.println(e.getMessage());


 
It prints the stack trace

 
It prints the error message for an exception

 
It prints the code that caused the exception

 
It overrides the toString method
  

QUESTION 22

1.      In a try/catch construct, after the catch statement is executed


 
The program returns to the statement following the statement in which the exception occurred

 
The program terminates

 
The program resumes at the statement that immediately follows the try/catch construct

 
The program resumes at the first statement of the try statement
   

QUESTION 23

1.      In the following code, assume that inputFile references a Scanner object that has been successfully used to open a file:


What will be the value of totalIncome after the following values are read from the file? 
2.5
8.5
3.0
5.5
abc
1.0


 
19.5

 
0.0

 
35.5

 
75.0
 

QUESTION 24

1.      Look at the following code:
  

 

DataInputStream inputFile =
new DataInputStream(new FileInputStream("MyInfo.dat"));

 

QUESTION 25

1.      The catch clause


 
follows the try clause

 
starts with the word catch followed by a parameter list in parentheses containing an ExceptionType parameter variable

 
contains code to gracefully handle the exception type listed in the parameter list

 
All of these
 
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