1. | Given the code
String s = new String("abc");
Which of the following calls are valid?
(A) s.trim()
(B) s.replace('a', 'A')
(C) s.substring(3)
(D) s.toUppercase()
(E) s.setCharAt(1,'A')
(F) s.append("xyz") |
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 Hint
Half-n-half Clue
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2. | The methods wait() and notify() are defined in |
| | Half-n-half Clue
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3. | Which of the following statements are valid array declaration?
(A) int number();
(B) float average[];
(C) double[] marks;
(D) counter int[]; |
| | Half-n-half Clue
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4. | 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: |
| | Half-n-half Clue
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5. | Consider the following code
int number[] = new int[5]; After execution of this statement, which of the following are true?
(A) number[0] is undefined
(B) number[5] is undefined
(C) number[4] is null
(D) number[2] is 0
(E) number.length() is 5 |
| | Half-n-half Clue
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6. | 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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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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