Quiz-1

As we have defined a constructor which takes an int parameter, so when we are trying to declare an object obj of class A without supplying any parameter then as a constructor is overwritten it will give an error saying that no matching function found. So whenever one writes a constructor then the default constructor is overwritten hence if you want to declare an object without parameter then you also have to define that constructor.

As the object is defined ony once in the program at line A B::a, so the constructor of A is called only once. For objects a1, a2 and a3 copy constructor is called so the string will not be printed for them.

A default constructor does not require any parameters for object creation that’s why sometimes we declare an object without any parameters.

The C++ compiler always provides a default constructor if one forgets to define a constructor inside a class.

There are three types of constructors in C++:

• Default constructor,


• Parameterized constructor,


• Copy constructor.

->(arrow operator) is used by a pointer object to access members of its class.

Virtual base classes are used in virtual inheritance in a way of preventing multiple “instances” of a given class appearing in an inheritance hierarchy when using multiple inheritances.

A default constructor is a constructor that either has no parameters, or if it has parameters, all the parameters have default values.

• A destructor is a member function with the same name as its class prefixed by a ~ (tilde). For example: class X { public: // Constructor for class X X(); // Destructor for class X ~X(); }; A destructor takes no arguments and has no return type. Its address cannot be taken.


• Destructors are usually used to deallocate memory and do other cleanup for a class object and its class members when the object is destroyed. A destructor is called for a class object when that object passes out of scope or is explicitly deleted. ... A destructor takes no arguments and has no return type.

If there is any one parametrized Constructor present in a class, Default Constructor will not be added at Compile time. So if your program has any constructor containing parameters and no default constructor is specified then you will not be able to create object of that class using Default constructor