Development Java Tutorial

public class MainClass 
{
   public static void main( String args[] )
   { 
      double f = 123.94536; 
      String s = "Happy Birthday"; 
      System.out.printf( "Using precision for floating-point numbers\n" );
      System.out.printf( "\t%.3f\n\t%.3e\n\t%.3g\n\n", f, f, f );  
   
      System.out.printf( "Using precision for strings\n" );
      System.out.printf( "\t%.11s\n", s );
   } // end main 
}
Using precision for floating-point numbers
123.945
1.239e+02
124
Using precision for strings
Happy Birth