oc-Foundation框架-NSString－常用方法-路径相关－拓展名

  NSString *path=@"/users/liyang/desktop/liyang.txt";
   NSLog(@"%@",[path pathExtension]);//返回路径的拓展名

NSString *path=@"/users/liyang/desktop/liyang.txt";
   NSLog(@"%@",[path stringByDeletingPathExtension]);//删掉拓展名

 NSString *path=@"/users/liyang/desktop/liyang.txt";
   NSLog(@"%@",[path stringByAppendingPathExtension:@"docr"]);//拼接一个拓展名