String m; do { Scanner in = new Scanner(System.in); System.out.println("請(qǐng)輸入字母："); m = in.next(); switch (m) { case "a": System.out.println("元音字母" + m); break; case "e": System.out.println("元音字母" + m); break; case "i": System.out.println("元音字母" + m); break; case "o": System.out.println("元音字母" + m); break; case "u": System.out.println("元音字母" + m); break; default: System.out.println("請(qǐng)輸入元音字母，謝謝?。?！"); break; } } while (!m.equals("a"));小括號(hào)里的條件寫(xiě)的equals，只有寫(xiě)一個(gè)的時(shí)候有效，把eiou寫(xiě)進(jìn)去的時(shí)候沒(méi)用。求大佬破解??！