Interested to Buy Any Domain ? << Click Here >> for more details...
what is virtual destructor
- 7 Answers
- 13053 Views
- L&T, TCS, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / isha
Dear friend , you have done a mistake..
Example:
class Employee {
virtual ~Employee() {}
};
class Manager : public Employee {
~Manager() {}
}
Employee * m = new Manager();//here was the mistake
delete m; // <--
| Is This Answer Correct ? | 9 Yes | 0 No |
Answer / kamil mohamed
virtual destructor is recommended when you want to destroy
(delete) an object through it's parent pointer. This good
habit enforces proper cleanup of derived classes
Example:
class Employee {
virtual ~Employee() {}
};
class Manager : public Employee {
~Manager() {}
}
Manager * m = new Employee();
delete m; // <--
| Is This Answer Correct ? | 6 Yes | 1 No |
Answer / rock
When a derived class object pointed to by a base class
pointer dynamically is deleted only the base class
destructor is invoked inorder to even invoke derived class
destructor we use virtual destructor.
class shape
{
virtual ~shape(){}
};
class circle:public shape
{
~circle(){}
};
void main()
{
shape *sh = new circle;
delete sh; //both the destructors are invoked
}
If virtual keyword is not added to the base class
destructor only the base class destructor is called.
| Is This Answer Correct ? | 3 Yes | 0 No |
Answer / pankajkolte
Virtual Destructor is used basically to ensure proper the
sequence of call to destructor.
class Employee {
virtual ~Employee() {}
};
class Manager : public Employee {
~Manager() {}
}
Employee * m = new Manager();//here was the mistake
delete m; // <-
In this case base class destructor if marked as virtual so
as derived class destructor will get called first then base
class destructor.
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / suresh.k (portblair)
Using virtual destructors, you can destroy objects without
knowing their type - the correct destructor for the object
is invoked using the virtual function mechanism. Note that
destructors can also be declared as pure virtual functions
for abstract classes.
if someone will derive from your class, and if someone will
say "new Derived", where "Derived" is derived from your
class, and if someone will say delete p, where the actual
object's type is "Derived" but the pointer p's type is your
class.
| Is This Answer Correct ? | 2 Yes | 4 No |
Answer / rahul
virtual destructor is just to remove the variable without
knowing its type.....
| Is This Answer Correct ? | 0 Yes | 3 No |
Normally virtual destructor is used to destroy a base class
object without knowing it's type...
| Is This Answer Correct ? | 0 Yes | 3 No |
write a code for this. serial_number contained in the header of the file will be read , if this serial number is less than a previous serial number within a successfully processed file, or is the same as another serial number within a successfully processed file, or if the field contains anything other than 7 digits, then the file must error with the reason ‘Invalid SERIAL_NUMBER’.
You attempt to query the data base with this command: SELECT name, salary FROM employee WHERE salary=(SELECT salary FROM employee WHERE last name='Wagner' OR dept no=233) Choose most appropriate option from the following: 1)Sub-queries are not allowed in the where clause. 2)a multiple row sub-query used with a single row comparison operator. 3)a single row query is used with a multiple row comparison operator.
What is interface in oop?
Can we create object of abstract class?
what is an instance of a class
What is the use of oops?
What is Inheritance, Multiple Inheritance, Shared and Repeatable Inheritance?
difference between structure and union.
What language is oop?
program for insertion ,deletion,sorting in double link list
for example A,B,C,D are class all the 4 class contain one method who() but the method who() implementaion is differnet among each class. the relation among the 4 class are A is base class and is inherited by B and C.and from this two B and C where D is inherited. the question is i want to display the output who() method in all the classes(A,B,C,D)the output of who() method is diferrent amond all the class(A,B,C,D) ------A------ virtuval who(print a) override | | who(print b) B C override who(print c) | | -------D------ override who(print d)
Which language is not a true object oriented programming language?
STL 
