Problem
I. Create a main() method with a switch statement that calls either a sum() OR factorial() method, depending on what selection the user of the program makes - ask the user to enter a selection (with System.out.println()), create a Scanner then read the user's input with a call to Scanner next(), then call the appropriate method in a switch (the String that was read from the call to Scanner.next() should be what you use as your switch condition).
II. Create a method, sum(), to include a FOR loop that will:
Get a scanner and input a number from the keyboard in main(). The method will take one parameter and calculate the sum up to that number. For example, if you pass 5, it it will calculate 1+2+3+4+5 and will return it back to main() method.
III. Create another method, factorial(), and repeat what was done for the sum() method above but compute the product instead.