default argument in C++

defaultargument.cpp

#include <iostream>


using namespace std;

void f(int x=0,int y=0,int z=0);

int main()
{
f(2);
f(1,2);
f(3,2,1);

return 0;

}
void f(int x,int y,int z)
{
   if(x!=0)
   {
       cout<<"x= "<<x<<endl;
   }
      if(y!=0)
   {
       cout<<"y= "<<y<<endl;
   }
      if(z!=0)
   {
       cout<<"z= "<<z<<endl;
   }
}