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

This could work:

if (printf("Hello") - strlen("Hello"))
    printf("Hello")
else
    printf("World")

This snippet emphasizes the return value of printf: The number of characters printed.