JAVA

how to check whether a character is vowel in java

public class CodeGrepper {
    public static boolean isVowel(char letter) {
        String vowels = "aeouiAEOUI";
        return vowels.indexOf(letter) != -1; 
    }
    public static void main(String[] args) {
        System.out.println(isVowel('a')); // true
        System.out.println(isVowel('z')); // false
    }
}