/*

Description:

The first input array contains the correct answers to an exam, like [“a”, “a”, “b”, “d”]. The second one is “answers” array and contains student’s answers.

The two arrays are not empty and are the same length. Return the score for this array of answers, giving +4 for each correct answer, -1 for each incorrect answer, and +0 for each blank answer(empty string).

If the score < 0, return 0. For example: checkExam(["a", "a", "b", "b"], ["a", "c", "b", "d"]) → 6 checkExam(["a", "a", "c", "b"], ["a", "a", "b", ""]) → 7 checkExam(["a", "a", "b", "c"], ["a", "a", "b", "c"]) → 16 checkExam(["b", "c", "b", "a"], ["", "a", "a", "c"]) → 0 */ const checkExam = (answers, responses) => {

const score = responses.reduce((total, response, index) => {

if (!response) return total

if (response === answers[index]) return total + 4

if (response !== answers[index]) return total – 1

return total

}, 0)

return score > 0 ? score : 0

}