Factorial Method

Now that main() is correct we can work on factorial. The factorial method is a separate module. Its parameter num is a int and it returns a long.

Parameters in Java are always call by value, which means that when factorial(int num) is called, the value from the invocation (in main) is copied into the parameter.

Here is the code:

// Calculate num factorial
  public static long factorial( int num )
  {
    long fct = 1;
    for ( int j=1; j<=num; j++ )
      fct *= j;
    return fct;
  }