StringBuilder实现字符反转拼接

解题思路:

注意事项:

参考代码:

                import java.util.Scanner;

                public class Main {

                 public static void main(String[] args) {

                 Scanner sc = new Scanner(System.in);

                 char [] arr = new char[20];

                 String a = sc.next();

                 int t = a.length();

                 for(int i=0;i<t;i++){

                 arr[i] = a.charAt(i);}

                 System.out.println(method(t,arr));

                 }

                 public static String method(int t,char [] arr){

                     StringBuilder y = new StringBuilder();

                     for(int i=t-1;i>=0;i--){

                         y.append(arr[i]);

                     }

                      return y.toString();

                 }

                }