AlternatingVowelTest.java

public class AlternatingVowelTest {

    /**
      * Program: AlternatingVowelTest.java by Chris Clarke
      * Date: 17.10.2020
      * For Yahoo! Answers
      */

    /* does string s have alternating vowels and consonants? */

    public static boolean isAlt (String s) {
        final String vowels = "aeiou";
        boolean shouldBeVowelNext = true;
        boolean foundVowel;

        for (int j=0; j<vowels.length(); j++) {
            if (s.charAt(0)==vowels.charAt(j)) {
                shouldBeVowelNext = false;
                break;
            }
        }

        for (int i=1; i<s.length(); i++) {
            foundVowel = false;
            for (int j=0; j<vowels.length(); j++) {
                if (s.charAt(i)==vowels.charAt(j)) {
                    foundVowel = true;
                    break;
                }
            }
            if (foundVowel != shouldBeVowelNext) return false;
            shouldBeVowelNext = !shouldBeVowelNext;
        }
        return true;
    }

    public static void main (String[] args) {
        String[] testData = {"amazon", "apple", "banana"};
        for (String word: testData) {
            if (isAlt (word)) {
                System.out.println (word + " is alternating between vowels & consonants.");
            } else {
                System.out.println (word + " is not alternating.");
            }
        }
    }
}