一个5位数，判断它是不是回文数。即12321是回文数，个位与万位相同，十位与千位相同

publicclass lesson1_31 {

       publicstaticvoid paduan(String num) {

              int j = 0, i = 0, count = 0;

              for (i = 0, j = num.length() - 1; i < num.length() / 2; i++, j--)

                     if (num.charAt(i) == num.charAt(j)) {

                            count++;

                     }

              if (count == num.length() / 2) {

                     System.out.println(num + "是回文数！");

              } else

                     System.out.println(num + "不是回文数！");

       }

       publicstaticvoid main(String[] args) {

              paduan("12321");

              paduan("123321");

              paduan("123467321");

       }

}

 

运行结果：

12321是回文数！

123321是回文数！

123467321不是回文数！