This document discusses different uses of the "this" pointer in C++ classes. This pointer points to the object whose member function is being called. It can be used to return the object from a member function, access the memory address of the object, and access data members within member functions. Sample programs are provided to demonstrate returning an object using this, displaying the memory address of an object using this, and accessing a data member within a member function using this->.

1. I N T R O D U C T I O N
U S I N G T H I S F O R R E T U R N I N G V A L U E S
U S I N G T H I S F O R S P E C I F Y I N G M E M O R Y A D D R E S S
U S I N G T H I S F O R A C C E S S I N G D A T A M E M B E R S
This Pointer

2. Introduction
 Every member function of the class is born with the
pointer called this which points to the object with
which member function is associated.
 When a member function is invoked it comes into
existence with the value of this set to the address of
the object for which it is called

3. Using this for returning values
 This pointer can be used to return the values from
the member function.
 Since it points to the address of the object which
called the member function, we can return the object
by value with the help of this pointer

4. Sample Program
#include<iostream.h>
#include<conio.h>
class num
{
int a,b;
public:
num(int x, int y)
{
a=x;b=y;
}
void display()
{
cout<<"a="<<a<<" and
b="<<b<<endl;
}
num add(num);
};
num num:: add(num x)
{
a=a+x.a;
b=b+x.b;
return *this;
}

5. void main()
{
clrscr();
num obj1(1,2),obj2(3,4);
obj1.display();
obj2.display();
obj1.add(obj2);
obj1.display();
getch();
}

6. OUTPUT

7. Using this for specifying memory address
 This pointer is created automatically inside the
member function whenever the member function is
invoked by the object.
 It holds the memory address of the object so it can be
used to access the memory address of the object

8. Sample Program
#include<iostream.h>
#include<conio.h>
class num
{
int a;
public:
void displayAddress()
{
cout<<"The memory
address of the object is
"<<this<<endl;
}
};
void main()
{
clrscr();
num obj1,obj2;
obj1.displayAddress();
obj2.displayAddress();
getch();
}

9. OUTPUT

10. Using this pointer for accessing the data member
 This pointer can also be used to access the data
members inside the member function.
 It can be done with the help of arrow operator(->)
 Arrow operator is the combination of hyphen(-) and
greater than operator(>)

11. Sample Program
#include<iostream.h>
#include<conio.h>
class num
{
int a;
public:
void display()
{
this->a=89;
cout<<"a= "<<this->a
<<endl;
}
};
void main()
{
clrscr();
num obj1;
obj1.display();
getch();
}

12. OUTPUT