Which of the following overloaded functions will b

Which of the following overloaded functions will be called in the main() function?

int main()
{
     f(3.4);
     return 0;
}

void f();
void f( int );
void f( double, double = 3.4 );
void f( char *, char * );

Explanation

For the function f(int), the conversion of the actual argument of type double to type int should be applied, which is one of the standard ones. For the function f(double, double), the type of the actual argument double exactly matches the type of the formal parameter. Since exact matching is better than the standard conversion, f(double, double) is considered the most suitable function for this call.