iOS 判断字符串是否以字母或者汉字开头

//  判断是否以字母开头
- (BOOL)isEnglishFirst:(NSString *)str {
    NSString *regular = @"^[A-Za-z].+$";
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regular];
    
    if ([predicate evaluateWithObject:str] == YES){
        return YES;
    }else{
        return NO;
    }
}
//  判断是否以汉字开头
- (BOOL)isChineseFirst:(NSString *)str {
    int utfCode = 0;
    void *buffer = &utfCode;
    NSRange range = NSMakeRange(0, 1);
    BOOL b = [str getBytes:buffer maxLength:2 usedLength:NULL encoding:NSUTF16LittleEndianStringEncoding options:NSStringEncodingConversionExternalRepresentation range:range remainingRange:NULL];
    if (b && (utfCode >= 0x4e00 && utfCode <= 0x9fa5)){
        return YES;
    }else{
        return NO;
    }
}