What is wrong in the following code?

public class Test {

  public static void main(String[] args) {
    GeometricObject x = new Circle(3);
    GeometricObject y = x.clone();
    System.out.println(x == y);
  }
}

What is wrong in the following code?

1. public class Test {
2.   public static void main(String[] args) {
3.    java.util.Date[] dates = new java.util.Date[10];
4.    System.out.println(dates[0]);
5.    System.out.println(dates[0].toString());
6.  }
7. }

What is wrong in the following code?

public class Test {

  public static void main(String[] args) {
    Number x = new Integer(3);
    System.out.println(x.intValue());
    System.out.println((Integer) x.compareTo(new Integer(4)));
  }
}

What is wrong in the following code ?

    public class Test {
        public static void main(String[] args) {
            GeometricObject x = new Circle(3);
            GeometricObject y = x.clone();
            System.out.println(x == y);
        }
    }
    ```

For the following code, which statement is NOT true?

public class Circle {
    private double radius;
    public int x;
    private int y;
}

A) y is available to code that is written outside the Circle class.

B) radius, x, and y are called fields of the Circle class.

C) x is available to code that is written outside the Circle class.

D) radius is not available to code written outside the Circle class.

What is the output of the following code? public class A { boolean x; public static void main(String[] args) { A a = new A(); System.out.println(a.x); } }

What is wrong in the following code ?

    public class C {
        private int p;

        public C() {
            System.out.println("C's no-arg constructor invoked");
            this(0);
        }

        public C(int p) {
            p = p;
        }

        public void setP(int p) {
            p = p;
        }
    }

What is wrong in the following code ?

    public class Test {
        private int id;
        public void m1() {
            this.id = 45;
        }
        public void m2() {
            Test.id = 45;
        }
    }

Show the output of the following code:

(a)
public class Test {
    public static void main(String[] args) {
        int[] a = {
            1,
            2
        };
        swap(a[0], a[1]);
        System.out.println("a[0] = " + a[0] +
            " a[1] = " + a[1]);
    }
    public static void swap(int n1, int n2) {
        int temp = n1;
        n1 = n2;
        n2 = temp;
    }
}

(b)

public class Test {
    public static void main(String[] args) {
        int[] a = {
            1,
            2
        };
        swap(a);
        System.out.println("a[0] = " + a[0] +
            " a[1] = " + a[1]);
    }
    public static void swap(int[] a) {
        int temp = a[0];
        a[0] = a[1];
        a[1] = temp;
    }
}

(c)

public class Test {
    public static void main(String[] args) {
        T t = new T();
        swap(t);
        System.out.println("e1 = " + t.e1 +
            " e2 = " + t.e2);
    }
    public static void swap(T t) {
        int temp = t.e1;
        t.e1 = t.e2;
        t.e2 = temp;
    }
}
class T {
    int e1 = 1;
    int e2 = 2;
}

(d)

public class Test {
    public static void main(String[] args) {
        T t1 = new T();
        T t2 = new T();
        System.out.println("t1's i = " +
            t1.i + " and j = " + t1.j);
        System.out.println("t2's i = " +
            t2.i + " and j = " + t2.j);
    }
}
class T {
    static int i = 0;
    int j = 0;
    T() {
        i++;
        j = 1;
    }
}

Show the output of the following two programs:

public class Test {
   public static void main(String[] args) {
      xMethod(5);
   }
   public static void xMethod(int n) {
      if (n > 0) {
         System.out.print(n + " ");
      }
   }
}

public class Test {
    public static void main(String[] args) {
        xMethod(5);
    }
    public static void xMethod(int n) {
        if (n > 0) {
            System.out.print(n + " ");
        }
    }
}

Show the output of the following code:

public class Test {
 public static void main(String[] args) {
 System.out.println("3.5 * 4 / 2 – 2.5 is ");
 System.out.println(3.5 * 4 / 2 – 2.5);
 }
}

Suppose the class F is defined in (a). Let f be an instance of F. Which of the statements in (b) are correct?

(The Time class) Design a class named Time. The class contains:

• The data fields hour, minute, and second that represent a time.
• A no-arg constructor that creates a Time object for the current time. (The values of the data fields will represent the current time.)
• A constructor that constructs a Time object with a specified elapsed time since midnight, January $1, 1970$, in milliseconds. (The values of the data fields will represent this time.)
• A constructor that constructs a Time object with the specified hour, minute, and second.
• Three getter methods for the data fields hour, minute, and second, respectively.
• A method named setTime (long elapseTime) that sets a new time for the object using the elapsed time. For example, if the elapsed time is $555550000$ milliseconds, the hour is $10$ , the minute is $19$ , and the second is $10$ .

Draw the UML diagram for the class then implement the class. Write a test program that creates three Time objects (using new Time (), new Time (555550000), and new Time $(5,23,55)$ ) and displays their hour, minute, and second in the format hour:minute:second. (Hint: The first two constructors will extract the hour, minute, and second from the elapsed time. For the no-arg constructor, the current time can be obtained using System. currentTimeMillis (), as shown in Listing 2.7, ShowCurrentTime.java. Assume the time is in GMT.)

Design a class named Queue for storing integers. Like a stack, a queue holds elements. In a stack, the elements are retrieved in a last-in first-out fashion. In a queue, the elements are retrieved in a first-in first-out fashion. The class contains: - An int[] data field named elements that stores the int values in the queue. - A data field named size that stores the number of elements in the queue. - A constructor that creates a Queue object with default capacity 8. - The method enqueue(int v) that adds v into the queue. - The method dequeue() that removes and returns the element from the queue. - The method empty() that returns true if the queue is empty. - The method getSize() that returns the size of the queue. Draw an UML diagram for the class. Implement the class with the initial array size set to 8. The array size will be doubled once the number of the elements exceeds the size. After an element is removed from the beginning of the array, you need to shift all elements in the array one position the left. Write a test program that adds 20 numbers from 1 to 20 into the queue and removes these numbers and displays them.