Static function

[wajahat]

I wanted to ask whether the function normalize in my code is a static function or not? and can static functions access non-static class members or not?
I have mentioned the keyword static in the prototype of the normalize function but not where I have defined it i.e.outside the class.Does it remain a static function or not?

#include<iostream>
#include<stdlib.h>


class Rational
{
		int *nptr;
		int * dptr;

    public:

     Rational()                //DMA in constructor
     {
      nptr=new int;
      dptr=new int;
     }

     Rational operator+(Rational & r)           //overloaded + operator
     {
     		Rational x;
        *(x.nptr)=(*(nptr))*(*(r.dptr))+(*(dptr))*(*(r.nptr));
        *(x.dptr)=(*(dptr))*(*(r.dptr));
          return x;
     }

     Rational operator-(Rational & r)           //overloaded - operator
     {
     		Rational x;
        *(x.nptr)=(*(nptr))*(*(r.dptr))-(*(dptr))*(*(r.nptr));
        *(x.dptr)=(*(dptr))*(*(r.dptr));
          return x;
     }

     Rational operator*(Rational & r)           //overloaded * operator
     {
     		Rational x;
        *(x.nptr)=(*(nptr))*(*(r.nptr));
        *(x.dptr)=(*(dptr))*(*(r.dptr));
          return x;
     }

     Rational operator/(Rational & r)           //overloaded / operator
     {
     		Rational x;
        *(x.nptr)=(*(nptr))*(*(r.dptr));
        *(x.dptr)=(*(dptr))*(*(r.nptr));
         return x;
     }

     Rational operator++(int)           //overloaded ++ postfix operator
     {
     		Rational x;
     		*(x.nptr)=*(nptr)+*(dptr);
      	*(x.dptr)=*(dptr);
      	return x;
     }

     Rational operator--(int)           //overloaded -- postfix operator
     {
     		Rational x;
     		*(x.nptr)=*(nptr)-*(dptr);
         *(x.dptr)=*(dptr);
      	return x;
     }


     Rational& operator=(const Rational& r) //overloaded = assignment operator
     {
    		if (this != &r)
         	{
            		delete [] nptr;
                 	delete [] dptr;
        				nptr = new int;
        				dptr= new int;
       				nptr=r.nptr;
       				dptr=r.dptr;
    			}
    		return *this;
     }


     friend istream& operator>>(istream& in, Rational& r);
     friend ostream& operator<<(ostream& out, Rational& r);
     friend bool operator ==(Rational & x,Rational& r);
     static void normalize(Rational & r);

};

	  bool operator ==(Rational &x,Rational& r)   //overloaded == operator
     {
     		Rational ::normalize(r);
     		Rational ::normalize(x);
     		if((*(x.nptr)==*(r.nptr))&&(*(x.dptr)==*(r.dptr)))
     			return true;
     		else
     			return false;
     }


	 void Rational:: normalize(Rational & r)     //rational normalization
    {
    		int temp;
    		int x=*(r.nptr);
    		int y=*(r.dptr);
    		while (y != 0)
    		{
     			temp = x % y;
     			x = y;
     			y = temp;
    		}
         int GCD=(x);
			*(r.nptr)/=GCD;
 			*(r.dptr)/=GCD;
    }

	istream& operator>>(istream& in, Rational &r)  //overloaded >> operator
 	{
 			cout<<"\n\nEnter numerator ";
   		in>>*(r.nptr);
   		cout<<"\nEnter denominator ";
   		in>>*(r.dptr);
         cout<<endl;
   		return in;
   }

   ostream& operator<<(ostream &out, Rational& r)  //overloaded << operator
   {
   		cout<<"(";out<<*(r.nptr);cout<<"/";out<< *(r.dptr);cout<<")";
         cout<<" ";
    		return out;
   }

void main()
{
Rational r1,r2,r3,r4;
cout<<"\nEnter 1st rational number";
cin>>r1;
cout<<"\n\nEnter 2nd rational number";
cin>>r2;

char ch,chx;
do
{
cout<<"\n\n~~~~~~~~~~~RATIONAL CALCULATOR~~~~~~~~~~~\n";
cout<<"\nPress 1 to perform addition";
cout<<"\nPress 2 to perform subtraction";
cout<<"\nPress 3 to perform multiplication";
cout<<"\nPress 4 to perform division";
cout<<"\nPress 5 to increment";
cout<<"\nPress 6 to decrement";
cout<<"\nPress 7 to check equality";
cout<<"\nPress 8 to normalize\n";
cin>>chx;
switch(chx)
{
 case '1':
cout<<"\n\n+++++++++++++++ADDITION++++++++++++++++\n\n";
Rational:: normalize(r1);
Rational:: normalize(r2);
   r3=r1+r2;
   cout<<r1<<"+ "<<r2<<"= "<<r3;

 break;

 case '2':
cout<<"\n\n--------------SUBTRACTION--------------\n\n";
Rational:: normalize(r1);
Rational:: normalize(r2);
 r3=r1-r2;
 cout<<r1<<"- "<<r2<<"= "<<r3;
 break;

case '3':
cout<<"\n\n*************MULTIPLICATION*************\n\n";
Rational:: normalize(r1);
Rational:: normalize(r2);
r3=r1*r2;
cout<<r1<<"* "<<r2<<"= "<<r3;
 break;

case '4':
cout<<"\n\n////////////////DIVISION/////////////////\n\n";
Rational:: normalize(r1);
Rational:: normalize(r2);
r3=r1/r2;
cout<<r1<<"/ "<<r2<<"= "<<r3;
 break;

case '5':
cout<<"\n\n++ ++ ++ ++ ++ INCREMENT ++ ++ ++ ++ ++ \n\n";
Rational:: normalize(r1);
Rational:: normalize(r2);
r3=r1++;
cout<<r1<<"++  = "<<r3;
cout<<endl;
r4=r2++;
cout<<r2<<"++  = "<<r4;
 break;

case '6':
cout<<"\n\n-- -- -- -- -- DECREMENT -- -- -- -- --\n\n";
Rational:: normalize(r1);
Rational:: normalize(r2);
r3=r1--;
cout<<r1<<"--  = "<<r3;
cout<<endl;
r4=r2--;
cout<<r2<<"--  = "<<r4;
break;

case '7':
cout<<"\n\n== == == == == EQUALITY == == == == ==\n\n";
Rational:: normalize(r1);
Rational:: normalize(r2);
if(r1==r2)
cout<<"r1 is EQUAL to r2";
else
cout<<"r1 is NOT EQUAL to r2";

 break;

case '8':
cout<<"\n\n~~~~~~~~~~~~~NORMALIZE~~~~~~~~~~~~~~\n\n";
cout<<"r1 ="<<r1;
Rational:: normalize(r1);
cout<<"\n\nAfter normalization r1 ="<<r1;
cout<<"\n\nr2 ="<<r2;
Rational:: normalize(r2);
cout<<"\n\nAfter normalization r2 ="<<r2;
cout<<endl;
break;
}

cout<<"\n\nPerform another operation(y/n)?  ";
cin>>ch;
}while(ch=='y');

cout<<endl<<endl;
system("pause");
}

[hamsterman]

It is enough to declare it static. That function is static. You can't access non-static members from a static function.

[Mathhead200]

You can access non-static members from a static function, but you need an instance of the object. The pointer "this" is not available in static functions, because you do not invoke them on a object.

[wajahat]

Thank you .