FACULTY OF
ENGINEERING
CSI1102/CSI1502A
Midterm
Examiners:
Rimon Elias (CSI 1102 Group A)
Aziz Abdesselam (CSI 1102 Group B)
Diana Inkpen (CSI 1102 Group C)
Wissam Itani (CSI 1502A)
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Name |
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Student
Number |
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Group
(A, B, C) |
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Total marks: 50
Duration: 80
minutes
Total
Number of pages: 12
Important Regulations:
1.
Students are allowed to bring in a single
letter-size page of notes.
2.
No calculators are allowed.
3.
A student identification cards (or another photo
ID and signature) is required.
4.
An attendance sheet shall be circulated and
should be signed by each student.
5.
Please answer all questions on this paper, in
the indicated spaces.
6.
The last page contains some extra space for rough work.
Part A [7 marks]
(1 mark each)
State whether the following statements are True of False. Use the answer sheet provided below to indicate your answer.
1. The following expression creates an object of
class Student:
Student
John;
2. An 8 bits datatype can
encode a maximum of 254 values.
3. Service methods declared
with public visibility violate encapsulation.
4. Two or more methods
within the same class may have the same name.
5. A static method of a
class can be used without creating objects of the class.
6. An inner class has
access to the private data of its outer class.
7. An array subscript should normally be of data type float.
Answer sheet: Part A
|
Question |
Answer |
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1.
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F |
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2.
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F |
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3.
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F |
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4.
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T |
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5.
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T |
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6.
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T |
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7.
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F |
Part B: Multiple
Choice [8 marks]
Indicate which one of the following choices is
correct. (Note: Only one of the
answers is correct and each question counts 1 mark each.) Use the answer sheet provided below to indicate your
answer.
1. A computer can directly understand only its own
___________.
a) machine language
b) assembly language
c) high-level language
d) none of the above
2. Which of the following is an invalid identifier
(variable name)?
a) _Test
b) TEST
c) 5test
d) test1
3. The OR (||) operator
a) has higher precedence
than the AND (&&) operator
b) stops evaluation upon
finding one condition to be true
c) associates from right to
left
d) is a ternary operator
4. An aggregate object
a)
contains
references to other objects
b)
is
represented by an open diamond at the aggregate end in a UML class diagram.
c)
both (a) and (b)
d)
none of
the above
5. A two dimensional array in Java is:
a)
an array
of arrays
b)
referenced
using 2 index values
c)
all of the above
d)
none of
the above
Questions 6, 7, and 8 refer to the following UML diagram:
6. UML diagram is a /an:
a)
Object
UML diagram
b)
Class
UML diagram
c)
Both (a)
and (b)
d)
None of
the above
7. variables numFaces and
faceValue are:
a)
private
b)
public
c)
static
d)
none of
the above
8. SnakeEyes is a driver class
that will create _________ objects of the class Die.
a)
zero
b)
one
c)
two
d)
three
Answer sheet: Part B
|
Question |
Answer |
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1.
|
A |
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2.
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C |
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3.
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B |
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4.
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C |
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5.
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C |
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6.
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B |
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7.
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A |
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8.
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C |
Part C
Complete the
following sentences by filling in the missing words: [7 marks]
(1 mark each)
1. Variable names actually
correspond to locations in ___________
2. Support methods should
be declared with _______ visibility.
3. A ________ is a special
method that has the same name as the class and has no return type.
4. The _________
________ is used in Java to free memory that is no longer used.
5. A ________ class is used
in Java to transform a primitive type into an object.
6. The elements of an array
are related by the fact that they have the same _________.
7. The process of placing
the elements of an array in order is called
________ the array.
Answer sheet: Part C
|
Question |
Answer |
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1.
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memory |
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2.
|
private |
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3.
|
constructor |
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4.
|
garbage collector |
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5.
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wrapper |
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6.
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type |
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7.
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sorting |
Part D
D.1. What does the following code print? [15
marks]
public
class Midterm
{
//------------------------------------------------------
// Sets prices for some fruits
//------------------------------------------------------
public static void main (String[] args)
{
PartD1 tester = new PartD1();
double
price1 = 0.86, price2 = 0.87;
Fruit a1 = new Fruit("Apples",
price1);
Fruit a2 = new Fruit("
double a3 = a1.getPrice() +
a2.getPrice();
System.out.println (a1 + "\t" + a2 +
"\t\t" + a3);
tester.changeValues
(a1, a2, a3);
System.out.println (a1 + "\t" + a2 + "\t\t" + a3);
}
}
//////////////////////////////////////////
public class PartD1
{
public void
changeValues (Fruit a1, Fruit a2, double a3)
{
a1.setValue("Grapes", a1.getPrice()*3);
a2 = new Fruit("Bananas",
a2.getPrice());
a3 = a1.getPrice() + a2.getPrice();
System.out.println (a1 + "\t" + a2 +
"\t\t" + a3);
}
}
///////////////////////////////////////
public
class Fruit
{
private String fruit;
private double price;
public Fruit (String fruit, double price)
{
setValue
(fruit, price);
}
public void setValue (String fruit, double
price)
{
this.fruit = fruit;
this.price = price;
}
public double getPrice ()
{
return price;
}
public String toString ()
{
return fruit + " = " + price;
}
}
Answer sheet Part D,
Question 1.
D.2. What does the following code print? Fill in the blanks in the
answer sheet below. [7
marks]
public class ShapeDriver
{
public static void main
(String[] args)
{
Shape s1 = new Shape (5);
System.out.println (s1);
Shape s2 = new Shape (7);
System.out.println (s2);
Shape s3 = new Shape (4);
System.out.println (s3);
System.out.println ("N
is: " + Shape.getN());
}
}
////////////////////////////
public class Shape
{
private int numLines;
private static int N = 0;
public Shape (int val)
{
numLines = val;
N = N + val;
}
public String toString()
{
return "Number of lines is
" +numLines + " and N is " +N;
}
public static int getN ()
{
return N;
}
}
Answer Sheet Part D,
Question 2
Number of lines is __5___ and N is __5__
Number of lines is __7___ and N is __12__
Number of lines is __4___ and N is __16__
N is: __16___
D. 3. Write a program that asks the user for a width and height of a rectangle and then outputs a hollow rectangle. The part that reads input is already written for you. The program only accepts valid input (numbers >= 3). Fill in the code for outputting the rectangle. The rectangle is composed of the character '*' and ' '. Therefore, a rectangle with a width of 8 and a height of 5 would appear as follows: [6 marks]
********
* *
* *
* *
********
![Text Box: import cs1.Keyboard;
public class rectangle {
public static void main(String args[])
{
int Width=0; int Height=0; int Counter1, Counter2;
while (Width < 3)
{
System.out.println("Enter the width of the rectangle");
Width = Keyboard.readInt();
if (Width < 3)
System.out.println("Error in input, try again");
}
while (Height < 3)
{
System.out.println("Enter the height of the rectangle");
Height=Keyboard.readInt();
if (Height < 3)
System.out.println("Error in input, try again");
}
// D.3 answer
for (Counter1 = 0; Counter1 < Width; Counter1++)
System.out.print("*");
System.out.println();
for(Counter2 = 0; Counter2 < Height-2; Counter2++)
{System.out.print("*");
for (Counter1 = 0; Counter1 < Width-2; Counter1++)
System.out.print(" ");
System.out.print("*");
System.out.println();
}
for (Counter1 = 0; Counter1 < Width; Counter1++)
System.out.println("*");
System.out.println();
}
}](Midterm2005_solution_files/image005.gif)