Recently MeroSpark is lunched with more features and services, now you can ask your question, sell your books, share your notes and many more. Visit now and create your account to take full advantage of MeroSpark.

Default Constructor – Object Oriented Programming (OOP)

Download our Android App from Google Play Store and start reading Reference Notes Offline.

Default ConstructorDefault Constructor – Reference Note
Object Oriented Programming (OOP)
Third Semester | Second year
BSc.CSIT | Tribhuvan University (TU)

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

If no user-defined constructor exists for a class A and one is needed, the compiler implicitly declares a default parameter less constructor A::A(). This constructor is an inline public member of its class. The compiler will implicitly define A::A() when the compiler uses this constructor to create an object of type A. The constructor will have no constructor initialize and a null body. For instance, consider the following example.

class A {
int i;
void getval(void);
void prnval(void);
//member function definitions
A ob1;
/* uses default constructor for creating ob1. Since user can use it, that means, this implicity defined constructor is public member of the class */

Having a default constructor simply means that an application can declare instances of the class. The compiler first implicitly defines the implicitly declared constructors of the base classes and non-static data members of a class A before defining the implicitly declared constructor of A. No default constructor is created for a class that has nay constant or reference type members.
A constructor of a class A is trivial if all the following statements are true;

  • It is implicitly defined
  • A has no virtual functions and no virtual base classes
  • All the direct base classes of A have trivial constructors
  • The classes of all the non-static data members of A have trivial constructors
  • The default constructor provided by the compiler does not do anything specific. It simply allocates memory to data members of the object.
(Visited 264 times, 1 visits today)

Posted By : Digvijay | Comment RSS | Category : Third Semester
Tag :

Post a Comment

Your email is never published nor shared. Required fields are marked *


Wordpress DMCA
Community | Toolbar | Android App | Founder/Developer : Hari Prasad Chaudhary | CSIT Portal Manager : Digvijay Chaudhary