使用遞歸算法反轉字符串

public class T {
    //反轉字符串
    public static String reverseString(String s){
        if(s.isEmpty()) return s;
        return reverseString(s.substring(1))+s.charAt(0);
    }
    
    public static void main(String[] args) {
        System.out.println(reverseString("123456789"));
    }
}