iOS 密码只包含数字或字母

- (BOOL)judgePassWordLegal:(NSString*)pwd{

    BOOLresult =false;

    if([pwdlength] >=6){

        // 判断长度大于8位后再接着判断是否同时包含数字和字符

        NSString * regex = @"^([0-9]|[a-zA-Z]){6,17}$";

        NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];

        result = [predevaluateWithObject:pwd];

    }

    returnresult;

}

正则表达式相关：http://www.cnblogs.com/zxin/archive/2013/01/26/2877765.html

密码包含数字和字母：https://blog.csdn.net/u011156012/article/details/47251553