refactor to use a function for plural vs singular
rather than ternary operator
take out do while, instead use infinite loop/break
clearer as do not repeat conditional
refactor do not keep count of total
Test using exercise example:
$ java E02DoWhile
Input a mark: 13
Input a mark: 45
Input a mark: 63
Input a mark: 73
Input a mark: 101
Input a mark: 45
Input a mark: 18
Input a mark: 92
Input a mark: -1
There are 7 students: 2 distinctions, 1 pass, 4 fails (plus 1 invalid)
finish exercise 02