Use a function prototype to enforce strong type checking : function prototype « Function « C++ Tutorial

1. C++ Tutorial
2. Function
3. function prototype

#include <iostream> 
#include <cstdlib> 
using namespace std; 


void f(int i); // prototype 
 
int main() 
{ 
  int x = 10;   
  f(x);
 
  return 0; 
} 
 
void f(int i) 
{ 
  i = i * i;  
  cout << i;
}

100