1. What is printed when the following statement is executed?

System.out.println(17 / 5 % 3 + 17 * 5 % 3);

1. 1

2. 4

3. 9

4. 42

5. 42.5

2. Consider the following method.

public void process(String s) { s = s.substring(2, 3) + s.substring(1, 2) + s.substring(0, 1); }

What is printed as a result of executing the following statements (in a method in the same class)?

String s = "ABCD"; process(s); System.out.println(s);

1. ABCD

2. CBA

3. CDBCA

4. CDBCAB

5. IndexOutOfBoundsException

3.

Suppose m is a two-dimensional array of size 4 by 4, with all its elements intialized to zeroes. What will be the values stored in m after fill(m) is called? The method fill is defined as follows:

public void fill(int[][] m) { int n = m.length; for (int i = 1; i < n - 1; i++) { for (int j = 1; j < n - 1; j++) m[i][j] = 1; } }

1. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2. 1 1 0 0 1 1 0 0 0 0 0 0 0 0 0 0

3. 0 0 0 0 0 1 1 0 0 1 1 0 0 0 0 0

4. 1 1 1 0 1 1 1 0 1 1 1 0 0 0 0 0

5. 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

4.

Which of the following statements will result in a syntax error?

1. String x = "123";

2. Integer x = "123";

3. Object x = "123";

4. String[] x = {"123"};

5. All of the above will compile with no errors.

5. What is printed as a result of executing the following statements?

   double x = 2.5, y = 1.99; System.out.println((int)(x/y) + (int)(x*y));

   1. 0

   2. 3

   3. 4

   4. 4.0

   5. 5

6. Which of the following expressions is true if and only if NOT all three variables a, b, and c have the same value?

   1. a != b && b != c

   2. a != b || b != c

   3. a >= b && b >= c && c >= a

   4. a > b || b > c || a > c

   5. !(a == b || b == c || a == c)

7. What is the result when the following code segment is compiled and executed?

   int m = 4, n = 5; double d = Math.sqrt((m + n)/2); System.out.println(d);

   1. Syntax error "sqrt(double) in java.lang.Math cannot be applied to int"

   2. 1.5 is displayed

   3. 2.0 is displayed

   4. 2.1213203435596424 is displayed

   5. ArithmeticException

8. For which of the following pairs of values a and b does the expression

   (a > 20 && a < b) || (a > 10 && a > b)

   evaluate to true?

   1. 5 and 0

   2. 5 and 10

   3. 15 and 10

   4. 15 and 20

   5. None of the above

9. What is printed as a result of executing the following code segment?

   List lst = new ArrayList(); for (int k = 1; k <= 6; k++) lst.add(new Integer(k)); for (int k = 0; k < 3; k++) { Integer i = lst.remove(k); lst.add(i); } for (Integer i : lst) System.out.print(i)

   1. 123456

   2. 456123

   3. 456321

   4. 246135

   5. IndexOutOfBoundsException

10. Which of the following methods are equivalent (always return the same value for the same values of input parameters)?

    	public boolean fun(int a, int b, int c) { if (a >= b) if (b >= c) return true; else return false; else return false; }
    	public boolean fun(int a, int b, int c) { if (a >= b && b >= c) return true; else return false; }
    	public boolean fun(int a, int b, int c) { return a >= b || b >= c; }

    1. I and II only

    2. I and III only

    3. II and III only

    4. All three are equivalent

    5. All three are different

11. Consider the following class.

    public class Matrix { private int[][] m; /** Initializes m to a square n by n array with all * the elements on the diagonal m[k][k] equal to 0 and * all other elements equal to 1 */ public Matrix(int n) { m = new int[n][n]; < missing code > } < other constructors and methods not shown > }

    Which of the following could replace < missing code > in Matrix's constructor, so that it compiles with no errors and works as specified?

    	for (int r = 0; r < n; r++) for (int c = 0; c < n; c++) m[r][c] = 1; for (int k = 0; k < n; k++) m[k][k] = 0;
    	for (int k = 0; k < n; k++) m[k][k] = 0; for (int r = 0; r < n; r++) for (int c = 0; c < n; c++) if (r != c) m[r][c] = 1;
    	for (int c = 0; c < n; c++) for (int r = 0; r < n; r++) if (r == c) m[r][c] = 0; else m[r][c] = 1;

    1. I only

    2. II only

    3. I and II only

    4. II and III only

    5. I, II and III

12. Which of the following statements about developing a Java program is FALSE?

    1. The main purpose of testing a Java program is to make sure it doesn't generate run-time exceptions.

    2. Hello.class, a Java class file obtained by compiling Hello.java under a Windows operating system can be executed on a Mac computer.

    3. The size of an int variable in Java is four bytes, the same under any operating system and computer model.

    4. At run time, int values are represented in the computer memory in the binary number system.

    5. Division of an integer value by zero in a Java program will cause a run-time ArithmeticException.