CS160

Final

Spring 2005

Name__________________________________

Lab Section Number______________________

email__________________________________

1. Make sure you answer all 7 questions. Some questions have several parts.
2. You have 110 minutes to complete the test.
3. Make sure your answers are easy to read, if I can't read them I will have to subtract the points.
4. This exam contributes 25% of the total grade for this course.

1. The following code has two classes, Animal and Driver. Give the output of the following code:

public class Animal

{

private String myType;

public Animal(String type)

{

myType = type;

}

public String getType()

{

return myType;

}

public void setType(String type)

{

myType = type;

}

public Animal changeType(Animal furry, Animal hairy)

{

Animal p1 = new Animal("Elephant");

furry = hairy;

System.out.println(furry.getType()); //************* print 1***********

System.out.println(hairy.getType()); //********** print 2************

furry.setType("Pig");

System.out.println(furry.getType()); //************print 3*************

System.out.println(hairy.getType());//************print 4*************

furry = p1;

System.out.println(furry.getType()); //************print 5*************

System.out.println(hairy.getType());//************print 6*************

return furry;

}}

/*******************************************/

public class Driver

{

public static void main(String [] args)

{

Animal animalOne = new Animal("Monkey");

Animal animalTwo = new Animal("Dog");

Animal big = animalOne;

animalOne = animalTwo.changeType(big, animalTwo);

System.out.println(animalOne.getType()); //***********print 7

System.out.println(animalTwo.getType()); //***********print 8

}

}

What is the out put at each print statement

Print 1: Print 5:

Print 2: Print 6:

Print 3: Print 7:

Print 4: Print 8:

1. Answer with very short answers the following questions:

A . How many parameters can a Constructor receive?

B. How many constructors can a class have?

 

C. How many values can a method return?

 

D. Can a method return an instance of a Class (an object)?

 

E. Write the method definition for the method call getBook (the definition should only be one line of code):

 

String name = library.getBook(new Title("Harvey "));

 

 

 

F. What is the answer to num=4%5;

 

G . Name a data type that allows a fractional part?

H. What is the keyword final used for?

1. Given the following code, give the output (all the output) of each print statement. If there is a loop that executes five times, and there is a print statement in that loop I want all five outputs of the print statement with the proper line by line output.

public class Seven

{

public static void main(String [] args)

{

int [] num = new int[7];

int [] temp = new int[4];

//first for loop

for (int i = 0; i<num.length; i++)

{

if( i%3 == 0)

num[i] = i;

else

num[i] = i+5;

System.out.println(i + " is " + num[i]); //Print statement one

}

//Second for loop

for(int j=temp.length-1; j >= 0; j--)

{

temp[j] = num[j*2];

System.out.println(j +" is " + temp[j]); //Print statement two

}

char letters[] = {'F', 'I', 'N', 'A', 'L'};

String name = new String(letters); //this will initialize name to a string with the value of the array

aMethod(letters, name);

for(int i=0; i<name.length(); i++)

System.out.println(letters[i] + " - "+ name.charAt(i)); //Print statement four

}

public static void aMethod(char sub[], String n)

{

n = n.replace('A', 'E');

sub[0] = 'B';

for(int i=0; i<sub.length; i++)

System.out.println(sub[i] + " - "+ n.charAt(i)); //Print statement three

}

}

Print statement one

Print statement two

Print statement three

Print statement four

public class ExceptionExample

{

public static void main(String [] args)

{

Test p1 = new Test();

try{

p1.sampleMethod();

}

catch(RuntimeException es)

{

System.out.println("First");

}

catch(IOException es)

{

System.out.println("Second");

}

catch(Exception e)

{

System.out.println("Third");

}

finally{

System.out.println("Fourth");

}

}

}

/*********************************************************/

public class Test

{

public Test()

{

}

public void sampleMethod() throws Exception

{

try{

throw new Exception("Fifth");

}

catch(IOException err)

{

System.out.println("Sixth");

throw new IOException("Seventh");

}

catch(Exception e)

{

System.out.println("Eighth");

throw new Exception("Nineth");

}

finally{

System.out.println("Tenth");

}

}

}

1. Given the following code, four classes TheMain, Mammal, Bear , and Whale , follow the rules of inheritance and give the output of the six print statements.

public class TheMain

{

public static void main()

{

Mammal m1 = new Mammal("black", 200);

Bear b1 = new Bear(500);

Whale w1 = new Whale(1200);

//Question one

System.out.println(b1.getWeight());

//Question two

System.out.println(m1.getWeight());

//Question three

System.out.println(w1.getColor());

//Question four

System.out.println(b1.getColor());

//Question five

System.out.println(w1.getWeight());

//Question six

System.out.println("The amount of count = " + Mammal.count);

}

}

 

/*******************************************************/

 

public class Mammal

{

protected int x;

protected String y;

public static int count = 1;

public Mammal()

{

y = "Tan";

x = 450;

count++;

}

public Mammal(String a)

{

y = a;

}

public Mammal(String a, int b)

{

y = a;

x = b;

}

public Mammal(int b)

{

x = b;

y = "White";

}

public int getWeight()

{

x++;

return x;

}

public String getColor()

{

return y;

}

public String getColor(String s)

{

return s;

}

}

/***********Bear Class*************/

 

public class Bear extends Mammal

{

private int x;

private String y;

public Bear(String a, int b)

{

y = a;

x = b;

}

public Bear( int b)

{

x = b;

y = "Brown";

}

public String getColor()

{

return super.getColor(y);

}

}

/****************** Whale Class ***************/

 

public class Whale extends Mammal

{

public static int count;

protected int x;

protected String y;

public Whale(int a)

{

super(a);

x = a;

y = "White";

count++;

}

public int getWeight(int a)

{

return x;

}

}

Question 1:

Question 2:

Question 3:

Question 4:

Question 5:

Question 6:

2.&3.

1.

4.

1. Mouse Starts here (The graphics are lost, so start out to the right of the applet)
2. Mouse moves to here (inside the applet frame)
3. Mouse clicks at location 2
4. Mouse Moves to here (back outside the frame).

public class myApplet extends Applet implements MouseListener

{

private String phrase;

private int flag;

public void init()

{

phrase = "CS 160 Complete";

flag =0;

addMouseListener(this);

}

public void paint(Graphics g)

{

if(flag==1){

g.setColor(Color.black);

g.drawString(phrase, 5, 15);

g.drawRect(10, 40, 20, 30);

}

else if(flag==2)

{

g.setColor(Color.blue);

g.drawString(phrase, 10, 5);

g.drawOval(30, 30, 10, 40);

}

else

{

g.setColor(Color.red);

g.drawString(phrase, 5, 25);

g.fillRect(10, 25, 30, 20);

}

}

public void mouseClicked(MouseEvent e)

{

flag=1;

repaint();

}

public void mousePressed(MouseEvent e)

{

phrase = "Here Comes CS221";

}

public void mouseReleased(MouseEvent e)

{

}

public void mouseEntered(MouseEvent e)

{

flag=2;

phrase = "Finally CS160 is over";

repaint();

}

public void mouseExited(MouseEvent e)

{

flag=1;

phrase = "Goodbye";

}

}

7. Short Answer:

for(int a = 2; a < 11; a++){

System.out.println(a);

}

•  How many times will the print statement be excuted?

•  What is the final value for a?

***********************************************************************

if (a < b && b > c)

System.out.print("print statement one\n");

else if( b < c || c < a)

System.out.print("print statement two\n");

else if( b == 3)

System.out.print("print statement three\n");

else

System.out.print("print statement four\n");

 

•  If a, b, and c were declared and initialized properly is it possible that a, b or c could have values that would result in none of the four print statements to print?

•  Given the following values a = 5; b = 3; c = 4, what would be printed to the screen?

•  Given the following values a = 3; b = 3; c = 3, what would be printed to the screen?

•  The if/else clause above would be an example of a "conditional statement"?

************************************************************************

int stop = 0;

do{

stop = 1;

System.out.print("print statement\n");

stop++;

}while(stop == 1) ;

•  How many times will the print statement be excuted?

int stop = 0;

while(stop != 1){

stop = 1;

System.out.print("print statement\n");

stop++;

}

•  How many times will the print statement be excuted?

count = 0;

while(count<20)

System.out.println(count);

count=count+2;

•  How many times will the print statement be excuted?

**************************************************************

count=0;

while(count<20);

System.out.println(count++);

Answers