public static void main(String[] args) {    char[] chars= new String("How old are you !? I don't understand").toCharArray();    System.out.println("the first:");    System.out.println(chars);         reverseWords(chars); //主要方法         System.out.println("the second:");    System.out.println(chars);  }      /**   * 會將數組里面的單詞 倒序排列 例如 how old are you -> you are old how   * @param chars   */  public static void reverseWords(char[] chars) {    reverseChars(chars,0,chars.length-1);    int begin = -1;    int end = 0;    for(int i=0;i<chars.length;i++){      char c = chars[i];      if((c>='a'&&c<='z')||(c>='A'&&c<='Z')||c=='/''){ //簡單的判斷了一下是否是連續的單詞        if(begin==-1){          begin = i;          end=i;        }else{          end=i;          if(i==chars.length-1){            reverseChars(chars,begin,end);          }        }      }else{        if(begin!=-1){          reverseChars(chars,begin,end);          begin=-1;          end=0;        }      }    }  }   /**   * 將char 一定范圍內的 字符 倒序排列 例如   hello -> olleh   * @param chars 數組   * @param begin 開始位置   * @param end  結束位置   */  public static void reverseChars(char[] chars, int begin, int end) {    while(end>begin){      char c = chars[begin];      chars[begin] = chars[end];      chars[end] = c;      begin++;      end--;    }  }