有String s1, String s2两个字符串，s1="adfg2354"……

有String s1, String s2两个字符串，s1=“adfg2354”；把s1倒转赋值到s2上输出，
不能出现其它变量。  还是动动手吧。不能用reserve

package com.mzb.part4;

public class StringReverse {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String s1 = "adfg2354";
		String s2 = "";

		for (int i = s1.length()-1; i >= 0; i--) {

			s2 += (s1.substring(i)).substring(0, 1);

		}
		System.out.println(s2);
	}
}