Constructor in C++
A class constructor is a special member function of a class that is executed whenever we create new objects
of that class.
A constructor will have an exact same name as the class and it does not have any return type at all, not even
void. Constructors can be very useful for setting initial values for certain member variables.
Special characteristics of Constructors:
• They should be declared in the public section
• They do not have any return type, not even void
• They get automatically invoked when the objects are created
• They cannot be inherited though derived class can call the base class constructor
• Like other functions, they can have default arguments
• You cannot refer to their address
•
Constructors cannot be
virtual
#include <iostream>
using namespace std;
class
Line {
public:
void setLength( double len );
double getLength( void );
Line();
//
This is the constructor
private:
double length;
};
// Member functions definitions including constructor
Line::Line(void) {
cout << "Object is being created" << endl;
}
void Line::setLength( double len )
{
length = len;
}
double Line::getLength( void
) {
return length;
}
//
Main function for the
program int main() {
Line line;
