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Signature _____________________ Name ________________________
cs11f ____ Student ID ____________________
CSE 11
Final
Fall 2008
Page 1 ___________ (20 points)
Page 2 ___________ (10 points)
Page 3 ___________ (16 points)
Page 4 ___________ (28 points)
Page 5 ___________ (7 points)
Page 6 ___________ (26 points)
Page 7 ___________ (16 points)
Page 8 ___________ (13 points)
Page 9 ___________ (10 points)
Total ___________ (146 points = 140 base points + 6 points EC [5%])
(Partial) Operator Precedence Table
Operators Associativity
* / % left to right
+ - left to right
< <= > >= left to right
== != left to right
&& left to right
|| left to right
= right to left
1) Which of the following are not valid Java identifiers? (Circle your answer(s).)
thirdLine 3rdLine line3 extends
S.E. South East SE Public
2) Using the operator precedence table above, evaluate each expression and state what gets printed. Remember
short-circuit evaluation with && and ||.
int i = 1, j = 2, k = 3, m = 2;
System.out.println( j >= i && k == m ); ________
System.out.println( i >= 1 || j < 4 ); ________
System.out.println( !( k > m ) ); ________
System.out.println( !((i > 4) || (j <= 6)) == ((i <= 4) && (j > 6)) ); _________
3) What gets printed?
int a = 2, b = 7;
System.out.println( -1 + ++a * 5 + 17 % 5 ); _________
System.out.println( 6 + b++ - 5 / 9 + 4 ); _________
4) What gets printed?
public class Question
public static void main( String[] args )
final int MAX = 6;
int i = -2, j = -3;
for (i = 4; i < MAX; ++i )
j = 5;
while ( j <= MAX )
System.out.println( i + " " + j );
++j;
System.out.println( i + " " + j );
7) A bear is an animal and a zoo contains many animals, including bears. Three classes Animal, Bear, and Zoo
are declared to represent animal, bear, and zoo objects. Which of the following is the most appropriate set of
declarations? ________
A B
class Animal extends Bear { ... } class Bear extends Animal { ... } class Zoo { class Zoo { private Animal[] zooAnimals; private Animal[] zooAnimals; } }
C D
class Animal extends Zoo { class Bear extends Animal, Zoo { ... } private Bear zooBear; }
E F
class Zoo extends Animal { class Bear extends Animal implements Zoo { ... } private Bear[] zooAnimals; }
8) An interface definition is limited to having only ______________________________ and
________________________________.
A concrete class cannot have ___________________________________ declared in its definition.
A _____________ class cannot have any subclasses.
The keyword to denote inheritance of interface is ______________________.
The keyword to denote inheritance of implementation is ______________________.
9) Complete the following method which is intended to return the largest integer in the array numbers.
public static int findMax( int[] numbers ) // Assume length of numbers > 0 { int positionOfMax = 0;
for ( int index = 1; _____________________________________; ++index ) { if ( ______________________________________________________ )
_______________________________________________________ ; } return numbers[positionOfMax]; }
10) What does the following method print as a result of the call F10( 5 )?
public void F10( int x ) { if ( x > 1 ) { F10( x โ 1 ); }
for ( int y = 1; y <= x; ++y ) { System.out.print( y + " " ); }
System.out.println(); }
11) Indicate whether each of the following parts of a Java program is (A-H) and where in the Java Runtime
Environment this lives (1-3)
A) Class (static) variable 1) Class Area
B) Instance variable 2) Object in the Heap
C) Local variable 3) Stack Frame in the Runtime Stack
D) Parameter
E) Constructor
F) Static method
G) Instance method
H) Class definition Java program part Java Runtime area
(Answer A-H in this column) (Answer 1-3 in this column)
public class F11 ________ F { public static char actor; ________ actor ________
private double elected; ________ elected ________
public double getElected() { return elected; } ________ getElected ________ }
public class SomeOtherClass ________ SomeOtherClass { public int digit; ________ digit ________
public static void main( String[] args ) { ________ main ________
________ args ________
... // *** Location 1 *** F11 ref1; ________ ref1 ________
ref1 = new F11(); (where ref1 is pointing) ________
SomeOtherClass ref2 = new SomeOtherClass(); ________ ref2 ________
... // *** Location 2 *** (where ref2 is pointing) ________ }
public boolean foo( char test ) { ... } ________ foo ________
________ test ________ }
Write a statement that could appear above at the line marked //*** Location 1 *** that prints the value of actor
in class F11.
Write a statement that could appear above at the line marked //*** Location 2 *** that assigns the value of
elected in the F11 object referenced by ref1 into the variable digit in the SomeOtherClass object referenced by
ref2. Note: elected is private. Also note the types of elected and digit.
14) The following method is intended to return true if x is between lower1 and upper1, inclusive, or between
lower2 and upper2, exclusive, and false otherwise. You can assume lower1 <= upper1 and lower2 <= upper2.
Write the body of the method below. Do not define any local variables. You can do this in a single statement.
public boolean between( int x, int lower1, int upper1, int lower2, int upper2 )
15) Complete the following method to satisfy the following (you can assume the length of array is > 0):
The value of n1 when output is the sum of all positive even values in array.
The value of n2 when output is the sum of all negative values in array.
public void method( int[] array )
int n1 = 0;
int n2 = 0;
System.out.println( n1 );
System.out.println( n2 );
16) Using methods getAA() and getBB() and accessing B17's String representation, complete the one line
body of the toString() below.
public class F16 extends B
private int aa;
private Location bb;
* Returns the String consisting of bb's String representation and B17's String
* representation and aa each separated by a space (in that order).
public String toString()
_______________________________________________________________________________ ;
/* Other methods including getAA() and getBB() */
17) In HW14, class Circle was defined to have a center Point and an int radius along with a few constructors
and various methods. Complete the following copy constructor and simplified draw() method for class Circle
making sure you do not directly access the center and radius members โ use the appropriate accessor/mutator
methods defined with the class as part of the assignment.
public abstract class Shape { private String name;
public Shape( String name ) { this.setName( name ); }
public abstract void draw( DrawingCanvas canvas );
// Other constructors and methods of class Shape assumed here.
} // end class Shape
public class Circle extends Shape { private Point center; private int radius;
- Define copy constructor here (use Point's copy constructor, not simple assignment). */ public Circle( Circle c ) {
} // end Circle copy ctor
- Define draw method here.
- Assume color set elsewhere. Just draw the filled shape with the appropriate
- objectdraw library method with 5 args: x, y, width, height, canvas.
- Note: The circle should be centered around the center Point! Do not use a move() method. */ public void draw( DrawingCanvas canvas ) {
} // end draw()
// Other constructors and methods of class Circle assumed here, including accessors/mutators.
} // end class Circle
18b) Use the class definitions on the previous page to answer the following:
Can we subclass/extend from Lion like this? Explain why or why not.
class LittleLion extends Lion { public LittleLion() { super( "Little Lion" ); } public String speak() { return "Little " + super.speak(); } }
Can we subclass/extend from Animal like this? Explain why or why not.
class Dog extends Animal { public Dog() { super( "Dog" ); } public String speak( String name ) { return name + " says Woof"; } }
If class Cat was defined as a final class (final class Cat extends Animal), can we define SuessCat like
this? Explain why or why not.
class SuessCat extends Cat { public String toString() { return "Cat in the Hat " + super.toString(); } }
Can we make abstract class Animal an interface instead of a class (interface Animal) and change class
Cat extends Animal to class Cat implements Animal? Explain why or why not.
If you were writing this exam, what two serious questions would you put on this exam?
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