Write code to swap Case
//package com.book2s; public class Main { public static void main(String[] argv) { String str = "book2s.com"; System.out.println(swapCase(str)); }//from w w w. j a v a 2 s .c om public static String swapCase(String str) { int strLen; if ((str == null) || ((strLen = str.length()) == 0)) { return str; } StringBuffer buffer = new StringBuffer(strLen); char ch = 0; for (int i = 0; i < strLen; i++) { ch = str.charAt(i); if (Character.isUpperCase(ch)) { ch = Character.toLowerCase(ch); } else if (Character.isTitleCase(ch)) { ch = Character.toLowerCase(ch); } else if (Character.isLowerCase(ch)) { ch = Character.toUpperCase(ch); } buffer.append(ch); } return buffer.toString(); } }