Java Program MCQ

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• When comparing java.io.BufferedWriter and java.io.FileWriter, which capability exist as a method in only one of two ?
  ক

  closing the stream

  খ

  flushing the stream

  গ

  writting to the stream

  ঘ

  writting a line separator to the stream

  ঙ

  None of these
• System class is defined in .................
  ক

  java.util package

  খ

  java.lang package

  গ

  java.io package

  ঘ

  java.awt package

  ঙ

  None of these
• Which keyword when applied on a method indicates that only one thread should execute the method at a time.
  ক

  volatile

  খ

  synchronized

  গ

  native

  ঘ

  static

  ঙ

  final
• What notifyAll() method do?
  ক

  Wakes up one threads that are waiting on this object's monitor

  খ

  Wakes up all threads that are not waiting on this object's monitor

  গ

  Wakes up all threads that are waiting on this object's monitor

  ঘ

  None of the above
• Which of the following constructor of class Thread is valid one?
  ক

  Thread(Runnable threadOb, int priority)

  খ

  Thread(int priority)

  গ

  Thread(Runnable threadOb, String threadName)

  ঘ

  Thread(String threadName, int priority)

  ঙ

  None of these
• When a class extends the Thread class ,it should override ............ method of Thread class to start that thread.
  ক

  start()

  খ

  run()

  গ

  init()

  ঘ

  go()
• In java a thread can be created by ..........
  ক

  Extending the thread class.

  খ

  Implementing Runnable interface.

  গ

  Both of the above

  ঘ

  None of these
• Which exception is thrown when an array element is accessed beyond the array size?
  ক

  ArrayElementOutOfBounds

  খ

  ArrayIndexOutOfBoundsException 

  গ

  ArrayIndexOutOfBounds

  ঘ

  None of these
• What happen in case of multiple catch blocks?
  ক

  Either super or subclass can be caught first.

  খ

  The superclass exception must be caught first.

  গ

  The superclass exception cannot caught first.

  ঘ

  None of these
• Which of the following blocks execute compulsorily whether exception is caught or not.
  ক

  finally

  খ

  catch

  গ

  throws

  ঘ

  throw
• Which keyword is used to specify the exception thrown by method?
  ক

  catch

  খ

  throws

  গ

  finally

  ঘ

  throw
• Which exception is thrown when divide by zero statement executes?
  ক

  NumberFormatException

  খ

  ArithmeticException

  গ

  NullPointerException

  ঘ

  None of these
• Which keyword is used to explicitly throw an exception?
  ক

  try

  খ

  throwing

  গ

  catch

  ঘ

  throw
• Exception generated in try block is caught in ........... block.
  ক

  catch

  খ

  throw

  গ

  throws

  ঘ

  finally
• In which of the following package Exception class exist?
  ক

  java.util

  খ

  java.file

  গ

  java.io

  ঘ

  java.lang

  ঙ

  java.net
• The class at the top of exception class hierarchy is .................
  ক

  ArithmeticException

  খ

  Throwable

  গ

  Object

  ঘ

  Exception
• Runnable is a _____ .
  ক

  class

  খ

  abstract class

  গ

  interface

  ঘ

  vaiable

  ঙ

  method
• In Java, declaring a class abstract is useful
  ক

  To prevent developers from further extending the class.

  খ

  When it doesn't make sense to have objects of that class.

  গ

  When default implementations of some methods are not desirable.

  ঘ

  To force developers to extend the class not to use its capabilities.

  ঙ

  When it makes sense to have objects of that class.
• Which of the following is a correct interface?
  ক

  <span class="key">interface</span> <span>A</span> <span class="braces">{</span> <span class="key">void</span> <span>print()</span> <span class="braces">{ } }</span>

  খ

  <span class="key">abstract interface <span>A <span class="braces">{ <span>print(); <span class="braces">}

  গ

  <span class="key">abstract interface</span> <span>A</span> <span class="braces">{</span> <span class="key">abstract void</span> <span>print();</span> <span class="braces">{ }}</span>

  ঘ

  <span class="key">interface</span> <span>A</span> <span class="braces">{</span> <span class="key">void</span> <span>print();</span> <span class="braces">}</span>
• Which of the following statements regarding abstract classes are true?
  ক

  An abstract class can be extended.

  খ

  A subclass of a non-abstract superclass can be abstract.

  গ

  A subclass can override a concrete method in a superclass to declare it abstract.

  ঘ

  An abstract class can be used as a data type.

  ঙ

  All of the above
• Which of the following declares an abstract method in an abstract Java class?
  ক

  public abstract method();

  খ

  public abstract void method();

  গ

  public void abstract Method();

  ঘ

  public void method() {}

  ঙ

  public abstract void method() {}
• Which of the following class definitions defines a legal abstract class?
  ক

  class A { abstract void unfinished() { } }

  খ

  class A { abstract void unfinished(); }

  গ

  abstract class A { abstract void unfinished(); }

  ঘ

  public class abstract A { abstract void unfinished(); }
• ____________ method cannot be overridden.
  ক

  super

  খ

  static

  গ

  final

  ঘ

  private

  ঙ

  None of these
• Which of the following for loops will be an infinite loop?
  ক

  for(; ;)

  খ

  for(i=0 ; i

  গ

  for(i=0; ; i++)

  ঘ

  All of the above
• In java, ............ can only test for equality, where as .......... can evaluate any type of the Boolean expression.
  ক

  switch, if

  খ

  if, switch

  গ

  if, break

  ঘ

  continue, if
• The main method should be static for the reason
  ক

  It can be accessed easily by the class loader.

  খ

  It can be accessed by every method or variable without any hindrance.

  গ

  It can be executed without creating any instance of the class.

  ঘ

  None of the above
• The finalize() method is called just prior to
  ক

  An object, variable or method goes out of scope.

  খ

  An object or variable goes out of scope.

  গ

  A variable goes out of scope.

  ঘ

  Before garbage collection.

  ঙ

  None of the above
• The implicit return type of a constructor is
  ক

  void

  খ

  A class object in which it is defined.

  গ

  There is no return type.

  ঘ

  None of the above
• The variables declared in a class for the use of all methods of the class are called
  ক

  reference variables

  খ

  objects

  গ

  instance variables

  ঘ

  None of these
• Which of the modifier can't be used for constructors?
  ক

  public

  খ

  private

  গ

  static

  ঘ

  protected