Page 84 - DCAP404 _Object Oriented Programming

Unit 4: Classes and Objects

integer int1, int2; Notes
int1.getdata();
int2.getdata();
cout <<“\n the value of x belonging to object int1 is “;
int1.disp();
cout <<“\n the value of x belonging to object int2 is “;
int2.disp();

integer int3; .
int3.swap(int1, int2); //int3 is just used to invoke the function
cout <<“ \nafter swapping “;
cout <<“\n the value of x belonging to object intI is “;
intl.disp();
cout <<“\n the value of x belonging to object int2 is “;
int2.disp() ;

cout<< “\n”;
getche();
}
You should get the following output.
Enter a value for x 15
Enter a value for x 50
the value of x belonging to object int is 15

the value of x belonging to object int2 is 50
after swapping
the value of x belonging to object int is 15

the value of x belonging to object int2 is 50
In the second method, the address of the object is passed to the function instead of a copy of the
object. The called function directly makes changes on the actual object used in the call. As against
the first method any manipulations made on the object inside the function will occur in the
actual object.

!
Caution The second method is more efficient as only the address of the object is passed and
not the entire object.

The following Program illustrates calling of a function by reference. The program declares a
class integer to represent the variable x and defines functions to input and display the value. The
function written to swap the integer values of the object takes the addresses of the objects.
#include<iostream.h>
#include<conio.h>

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