java基础之字符串字母大小写转换、倒序

/** *  字符串字母大小写转换、并倒序输出 *  zzl */public class Shuffle {public static void main(String[] args) {       String str = "SDdfsDdSwqrewASDASD";              //字符串转成char数组       char [] ch = str.toCharArray();              StringBuffer buffer = new StringBuffer();              for(int i=str.length()-1;i>=0;i--){       if(ch[i]>='A'&&ch[i]<='Z'){       buffer.append(String.valueOf(ch[i]).toLowerCase());       }else if(ch[i]>='a'&&ch[i]<='z'){       buffer.append(String.valueOf(ch[i]).toUpperCase());       }       }       System.out.println(buffer.toString());}}