不知道怎么改啊
//实现字符串的逆转import java.io.*;
import java.util.*;
class WriteBackWard{
public static void main(String[] args){
String s="cat";
System.out.println("enter writebackward ,string"+s);
String writebackward(String s){
if(s.length()==0 ){}
//{do nothing --this is the base case}
else
{
System.out.println("About to write the cast derection of string"+s);
System.out.println(s.substring(s.length()-1,s.length()));
s=s.substring(s.length()-1,s.length());
writebackward(s);
}//end if
}//end function
}//end main
}//the end
