public class StringDemo { public static void main(String[] args) { String text = "hello"; System.out.println("字串內容: " + text); System.out.println("字串長度: " + text.length()); System.out.println("等於hello? " + text.equals("hello")); System.out.println("轉為大寫: " + text.toUpperCase()); System.out.println("轉為小寫: " + text.toLowerCase()); } }