代碼如下：
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("請輸入字符串：");
String arr = scanner.next();
String str = "";
for (int j = 0; j < arr.length(); j++) {
str = arr.charAt(j)+str;
}
System.out.println(str);
}
運行結果：
