1. | Given the class definitions
class Base
{
void display ()
{ System.out.println("Base"); }
}
class Derived extends Base
{
void display ()
{ System.out.println("Derived"); }
}
and objects
Base b = new Base();
Derived d = new Derived();
Base bd = new Derived;
then the print statements
System.out.print(b.display() + " ");
System.out.print(d.display() + " ");
System.out.print(bd.display() + " ");
System.out.println();
will display: |
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 Hint
Half-n-half Clue
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2. | Which of the following classes are available in the java.lang package?
(A) Stack
(B) Object
(C) Math
(D) Random
(E) String
(F) StringBuffer
(G) Vector |
| | Half-n-half Clue
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3. | The methods wait() and notify() are defined in |
| | Half-n-half Clue
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4. | Which of the following statements are true?
(A) A Java monitor must either extend Thread or implement Runnable.
(B) The sleep() method should be enclosed in try ... catch block.
(C) The yield() method should be enclosed in try ... catch block.
(D) A thread can be temporarily suspended from running by using the wait() method.
(E) A suspended thread using suspend() method can be revived using the resume() method. |
| | Half-n-half Clue
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5. | When we implement the Runnable interface, we must define the method |
| | Half-n-half Clue
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6. | Suppose that s1 and s2 are two strings. Which of the statements or expressions are valid?
(A) String s3 = s1 + s2;
(B) String s3 = s1 - s2;
(C) s1 <= s2
(D) s1.compareTo(s2);
(E) int m = s1.length(); |
| | Half-n-half Clue
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7. | Which of the following are the wrapper classes?
(A) Random
(B) Byte
(C) Vector
(D) Integer
(E) Short
(F) Double
(G) String |
| | Half-n-half Clue
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