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()); 
    } 
}