‘this’ pointer in C++

The ‘this’ pointer is passed as a hidden argument to all nonstatic member function calls and is available as a local variable within the body of all nonstatic functions. ‘this’ pointer is a constant pointer that holds the memory address of the current object. ‘this’ pointer is not available in static member functions as static member functions can be called without any object (with class name).
For a class X, the type of this pointer is ‘X* const’. Also, if a member function of X is declared as const, then the type of this pointer is ‘const X *const’.

Following are the situations where ‘this’ pointer is used:

1) When local variable’s name is same as member’s name

#include
using namespace std;
 
/* local variable is same as a member's name */
class Test
{
private:
   int x;
public:
   void setX (int x)
   {
       // The 'this' pointer is used to retrieve the object's x
       // hidden by the local variable 'x'
       this->x = x;
   }
   void print() { cout << "x = " << x << endl; }
};
 
int main()
{
   Test obj;
   int x = 20;
   obj.setX(x);
   obj.print();
   return 0;
}

Output:

x = 20

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