Constructors And Methods MCQ

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• #VALUE!
  ক

  JVM

  খ

  JDK

  গ

  JIT

  ঘ

  JRE
• What is the stored in the object obj in following lines of Java code?<br><pre><code class="java">box obj;</code></pre>
  ক

  Memory address of allocated memory of object

  খ

  NULL

  গ

  Any arbitrary pointer

  ঘ

  Garbage
• Which of the following is a method having same name as that of it's class?
  ক

  finalize

  খ

  delete

  গ

  class

  ঘ

  constructor
• What is not the use of "this" keyword in Java?
  ক

  Passing itself to another method

  খ

  Calling another constructor in constructor chaining

  গ

  Referring to the instance variable when local variable has the same name

  ঘ

  Passing itself to method of the same class
• <pre><code class="java">class A{ A(String s){} A(){}}class B extends A{ B(){} B(String s){ super(s); } void test(){ // insert code here }}</code></pre><br>Which of the below code can be insert at line 7 to make clean compilation ?
  ক

  A a = new B();

  খ

  A a = new B(5);

  গ

  A a = new A(String s);

  ঘ

  All of the above

  ঙ

  None of these
• What is the output for the below code?<br><pre><code class="java">public class Test{ public static void printValue(int i, int j, int k){ System.out.println("int"); } public static void printValue(byte...b){ System.out.println("long"); } public static void main(String... args){ byte b = 9; printValue(b,b,b); }}</code></pre>
  ক

  long

  খ

  int

  গ

  Compilation fails

  ঘ

  Compilation clean but throws RuntimeException

  ঙ

  None of these
• <pre><code class="java">public class MyClass{ }</code></pre><br>For the above class(MyClass) what is the correct way of declaring constructor?
  ক

  MyClass(){}

  খ

  MyClass(void) {}

  গ

  public MyClass(){}

  ঘ

  public MyClass(void){}

  ঙ

  1 and 3
• What is the prototype of the default constructor?<br><pre><code class="java">public class Test { }</code></pre>
  ক

  public Test(void)

  খ

  Test( )

  গ

  Test(void)

  ঘ

  public Test( )

  ঙ

  None of these
• Which of the following statements regarding static methods are correct?<br>1. Static methods are difficult to maintain, because you can not change their implementation.<br>2. Static methods can be called using an object reference to an object of the class in which this method is defined.<br>3. Static methods are always public, because they are defined at class-level.<br>4. Static methods do not have direct access to non-static methods which are defined inside the same class.
  ক

  1 and 2

  খ

  2 and 4

  গ

  3 and 4

  ঘ

  1 and 3
• 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
• In which area of memory, the system stores parameters and local variables whenever a method is invoked?
  ক

  Heap

  খ

  Storage Area

  গ

  Stack

  ঘ

  Array
• Which of the following options is the best for generating random integer 0 or 1?
  ক

  (int)Math.random()

  খ

  (int)Math.random() + 1

  গ

  (int)(Math.random() + 0.5)

  ঘ

  (int)(Math.random() + 0.2)
• What will be the return type of a method that not returns any value?
  ক

  void

  খ

  int

  গ

  double

  ঘ

  None of the above
• In Java, what is the purpose of method overloading?
  ক

  Defining multiple methods with the same name but different parameters

  খ

  Hiding methods in a superclass

  গ

  Redefining methods in a subclass

  ঘ

  Calling methods from other classes
• What is the difference between a method declaration and a method definition in Java?
  ক

  Declaration specifies method name, return type, and parameters; definition provides the implementation

  খ

  Declaration is used for constructors, and definition is used for regular methods

  গ

  Declaration is optional, and definition is mandatory

  ঘ

  Declaration and definition are the same in Java
• In Java, what does the "final" keyword indicate when used with a method?
  ক

  The method cannot be overridden in subclasses

  খ

  The method is a static method

  গ

  The method is a constructor

  ঘ

  The method cannot be accessed from other classes
• What is a non-static (instance) method in Java?
  ক

  A method that belongs to an instance of a class

  খ

  A method that cannot be called on objects

  গ

  A method that is marked as "static"

  ঘ

  A method that returns a static value
• In Java, which access modifier allows a method to be accessed from any class in any package?
  ক

  public

  খ

  private

  গ

  protected

  ঘ

  default (package-private)
• What is method signature in Java?
  ক

  The method name and its parameter types

  খ

  The method's return type

  গ

  The method's access modifier

  ঘ

  The method's implementation
• In Java, can a method have the same name as the class?
  ক

  Yes, it is a constructor

  খ

  Yes, it is a static method

  গ

  Yes, it is a public method

  ঘ

  No, it is not allowed
• What is the purpose of the "return" statement in a method in Java?
  ক

  To specify the method's access modifier

  খ

  To indicate that the method should return a value

  গ

  To stop the execution of the program

  ঘ

  To indicate the method is static
• Which keyword is used to declare a method that cannot be overridden in Java?
  ক

  final

  খ

  static

  গ

  abstract

  ঘ

  private
• What is method chaining in Java?
  ক

  Calling multiple methods on the same object in a single line

  খ

  Running methods concurrently

  গ

  Defining methods with the same name

  ঘ

  Using methods to chain objects together
• In Java, which keyword is used to define an abstract method?
  ক

  abstract

  খ

  method

  গ

  void

  ঘ

  public
• What is the purpose of method parameters in Java?
  ক

  To pass values into a method

  খ

  To define local variables

  গ

  To specify the return type

  ঘ

  To create instance variables
• Which keyword is used to call the constructor of the superclass in a subclass constructor?
  ক

  super

  খ

  this

  গ

  extends

  ঘ

  constructor