用递归机制逆序输出一个字符串

 1 package fa.ct;
 2 
 3 public class Nixu {
 4 
 5     static String input="abcdefg";
 6     public static  String ltof(String input){
 7         if(input.isEmpty()){
 8             return input;
 9         }
10         return ltof (input.substring (1)) + input.charAt (0);
11     }
12     public static void main(String[] args) {
13         System.out.println(input);
14         System.out.println(ltof(input));
15     }
16 
17 }