text: //
  //  NSString+Reverse.h
  //  CRC16Demo
  //
  //  Created by xzw on 17/8/3.
  //  Copyright © 2017年 xzw. All rights reserved.
  //
  
  #import <Foundation/Foundation.h>
  
  @interface NSString (Reverse)
  
  //两位逆序反转，1201->0112
  -(NSMutableString *)twoBitReverse;
  
  @end
  