Question : method with parameter

Hi,

I ran following program.

public class Class4
{
   public static void main( String args[] )
   {
      GradeBook4 myGradeBook = new GradeBook4();

      String courseName = "Java ";
      myGradeBook.displayMessage( courseName );
   }

}

class GradeBook4
{
   public void displayMessage( String courseName )
   {
      System.out.printf( "Welcome to the grade book for\n%s!\n",
         courseName );
   }

}

got output as
Welcome to the grade book for
Java !


My question is
how we got this output. Usually i concatenate the string message with + operator to display declared variables etc.
I also not clear where from ! is getting printed in output. Any links, ideas, sample code highly apppreciated. Thanks in advance

Answer : method with parameter

>>when i give like

System.out.printf( "Welcome to the grade book for\n%s!\n"+courseName );
>>

because it's expecting a parameter, which you're not giving it. See aforementioned docs