判断纯数字，字母，字符

// 判断是否为纯数字
- (BOOL)isPureNumandCharacters:(NSString *)string
{
string = [string stringByTrimmingCharactersInSet:[NSCharacterSet decimalDigitCharacterSet]];
if(string.length > 0)
{
return NO;
}
return YES;
}
// 判断是否为纯字母
-(BOOL)PureLetters:(NSString*)str{

   for(int i=0;i

       unichar c=[str characterAtIndex:i];

       if((c<'A'||c>'Z')&&(c<'a'||c>'z'))

           return NO;

   }

   return YES;

}

// 判断是否为纯符号

-(BOOL)isIncludeSpecialCharact: (NSString *)str {

   str = [str stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString: @"-/:;()¥&@\".,?!'"]];

   if(str.length > 0)

   {

       return NO;

   }

   return YES;

}