function with no arguments ,,

 #include<iostream>

#include<conio.h>

using namespace std;

//void add(void);

int sub(int ,int);

int main()

{

int a,b;

cout<<"enter the two variable:"<<endl;

cin>>a>>b;

// add();

sub(a,b);

getch();

return 0;

}

/*void add()

{

int x,y;

cout<<"addition is :"<<x+y;

}*/

int sub(int,int)

{

cout<<"substraction is:"<<a-b;

}