Here you can find the source of invert(String s)
public static String invert(String s)
//package com.java2s; /*//from w w w. ja v a 2 s .c o m * Mentawai Web Framework http://mentawai.lohis.com.br/ * Copyright (C) 2005 Sergio Oliveira Jr. (sergio.oliveira.jr@gmail.com) * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ public class Main { public static String invert(String s) { StringBuilder sb = new StringBuilder(s.length()); for (int i = s.length() - 1; i >= 0; i--) { sb.append(s.charAt(i)); } return sb.toString(); } }