The this Pointer

• Every object maintains a pointer to itself. The pointer is called the this pointer
• Operations performed by member functions on data members of an object are internally performed by using the object's dereferenced this pointer. For example given the following class definition:
  

  class ABC{
  public:
  	void init();
  private:
  	int x, y;
  };

  
  
  The following two implementations of the init() function are equivalent:
  

  
  void ABC::init(){
  	x = 0;
  	y = 0;
  }
  
  void ABC::init(){
  	(*this).x = 0;
  	(*this).y = 0;
  }
  

• The this pointer is commonly used to chain function calls. For example, consider the following code:
  

  
  #include<iostream.h>
  
  class demo{
  public:
  	demo& foo1();
  	demo& foo2();
  	demo& foo3();
  };
  
  demo& demo::foo1()
  {
  	cout << "Calling foo1()..." << endl;
  	return *this;
  }
  
  demo& demo::foo2()
  {
  	cout << "Calling foo2()..." << endl;
  	return *this;
  }
  
  demo& demo::foo3()
  {
  	cout << "Calling foo3()..." << endl;
  	return *this;
  }
  
  int main()
  {
  	demo chain;
  	chain.foo1().foo2().foo3(); //Chained function calls
  	return(0);
  }
  
  Output:
  
  Calling foo1()...
  Calling foo2()...
  Calling foo3()...