Chapter 6, Problem 6.2PE

(Sum the digits in an integer) Write a method that computes the sum of the digits in an integer. Use the following method header:

public static int sumDigits(long n)

For example, sumDigits (234) returns 9 (= 2 + 3 + 4). (Hint: Use the % operator to extract digits and the / operator to remove the extracted digit. For instance, to extract 4 from 234, use 234 % 10 ( = 4). To remove 4 from 234, use 234 / 10 (= 23). Use a loop to repeatedly extract and remove the digit until all the digits are extracted. Write a test program that prompts the user to enter an integer then displays the sum of all its digits.