What's the “condition” in C interview test?

Question

Would it be possible to print Hello twice using single condition?

if  \"condition\"
  printf (\"Hello\");
else
  printf(\"World\");         


        

Answer 1

 #include
  int main()
{
 if(! printf("Hello"))
     printf ("Hello");
else
    printf ("World");
 return 0;
}

Because Printf returns the number of character it has printed successfully.