// FactorialCalculator.java
// Recursive factorial method.

public class FactorialCalculator
{
   // recursive declaration of method factorial
   public long factorial( long number )
   {
      if ( number <= 1 ) // test for base case
         return 1; // base cases: 0! = 1 and 1! = 1
      else // recursion step
         return number * factorial( number - 1 );
   } // end method factorial

   // output factorials for values 0-10
   public void displayFactorials()
   {
      // calculate the factorials of 0 through 10
      for ( int counter = 0; counter <= 10; counter++ )
         System.out.printf( "%d! = %d\n", counter, factorial( counter ) );
   } // end method displayFactorials
} // end class FactorialCalculator