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Can a wild card or string "contains" be used in a switch {case}? caution: wordy

Being new to programming I read a lot of sample code and try to hack things together in an attempt to learn what works. I am working with html agility pack trying to scrap a news webpage.

Problem: One of the nodes that I am testing does not use a static value, it uses time of viewing. How can I apply this to a switch {case} method. I am also open for any suggestions if I am way off base in this entire approach.

Note also: I don't need to capture this node, if there is a way to skip it that works for me.

I decided to use an exapmle that uses a switch,

var rows = doc.DocumentNode.SelectNodes(".//*[@id='weekdays']/tr");
            foreach (var row in rows)
            {
                var cells = row.SelectNodes("./td");
                string title = cells[0].InnerText;
                var valueRow = cells[2];
                switch (title)
                {
                    case "Date":
                        HtmlNode date = valueRow.SelectSingleNode("//*[starts-with(@id, 'detail_row_seek')]/td");
                        Console.WriteLine("UPC=A:\t" + date.InnerText);
                        break;

                    case "":
                        string Time = valueRow.InnerText;
                        Console.WriteLine("Time:\t" + Time);
                        break;


                    case "News":
                        string Time = valueRow.InnerText;
                        Console.WriteLine("News:\t" + News);
                        break;
                }

excerpt of html

<table id="weekdays" cellpadding="6" cellspacing="0" border="0" width="100%">
                    <tr>
                        <td class="thead" style="border-bottom: 1px solid #d1d1e1;font-weight:normal; text-align: center; width:8%; padding-left: 6px;">Date</td>
                        <td class="thead" style="border-bottom: 1px solid #d1d1e1;font-weight:normal; width:8%; text-align: center; white-space:nowrap"><a href="guestcp.php?do=customoptions" title="Time &amp; Date Options"><img style="position:relative; vertical-align: bottom;" src="images/misc/clock_small.gif" title="Time &amp; Date Options" alt="Time &amp; Date Options" border="0" /></a><a href="guestcp.php?do=customoptions" title="Time &amp; Date Options"><span id="ff_nowtime_clock">3:20pm</span></a></td>
                        <td class="thead" style="border-bottom: 1px solid #d1d1e1;font-weight:normal; text-align: center; width:8%;">News</td>

.........

    开发者_如何学C                <tr id="detail_row_seek_37876">

        <td id="toprow_9" class="alt1 espace" rowspan="3" style="vertical-align: top; text-align: center;" nowrap="nowrap">
            <span class="smallfont">
                <div>Sat</div>
                Apr 9
            </span>
        </td>

    <td class="alt1 espace" style="text-align: center;" nowrap="nowrap">

            <span class="smallfont">Day 3</span>


    </td>
    <td class="alt1 espace" style="text-align: center;"><span class="smallfont">EUR</span></td>
    <td class="alt1 espace" style="padding-top: 2px" align="center">


<a name="chart=37876" style="position:absolute; margin-top: -10px;"></a><a name="details=37876" style="position:absolute; margin-top: -10px;"></a>


<div class="cal_imp_medium" title="Medium Impact Expected"></div></td>
    <td class="alt1 espace">

        <div class="smallfont" id="title_37876" style="padding-left: 11px;">ECOFIN Meetings</div>

    </td>

The problem is: The so called time column is not static it actual uses a time value. Is there a way to use a wild card in the case or a way to do a "contains" to get around this very wordy problem?


You must use constant values in each case of the switch statement.

The only way I can think of for you to do what you are looking to do is to use the default: case - within this default case you can test the value you are looking for using a contains, Parse or Regex test using if.

I couldn't quite follow your HTML sample code (sorry!) - but the modified C# might look something like:

            switch (title)
            {
                case "Date":
                    HtmlNode date = valueRow.SelectSingleNode("//*[starts-with(@id, 'detail_row_seek')]/td");
                    Console.WriteLine("UPC=A:\t" + date.InnerText);
                    break;


                case "News":
                    string News = valueRow.InnerText;
                    Console.WriteLine("News:\t" + News);
                    break;

                default:
                    if (regexTime.Match(title))
                    {
                        string Time = valueRow.InnerText;
                        Console.WriteLine("Time:\t" + Time);
                    }
                    break;
            }


You could use the "case default:" and put a condition inside that would check.

 switch (title) {
                    case "Date":
                        HtmlNode date = valueRow.SelectSingleNode("//*[starts-with(@id, 'detail_row_seek')]/td");
                        Console.WriteLine("UPC=A:\t" + date.InnerText);
                        break;

                    case "News":
                        string Time = valueRow.InnerText;
                        Console.WriteLine("News:\t" + News);
                        break;

                    case default:
                        if (whatever you need) {
                            ...
                        }
                        break;
                }


The case has to be a constant expression. see MSDN. If you can switch to using if-else, you'll have more freedom.


Add a default implementation, and put your extra condition checks there. Or you may be better off with just if statements.

switch (title)
        {
            case "Date":
                HtmlNode date = valueRow.SelectSingleNode("//*[starts-with(@id, 'detail_row_seek')]/td");
                Console.WriteLine("UPC=A:\t" + date.InnerText);
                break;

            case "":
                string Time = valueRow.InnerText;
                Console.WriteLine("Time:\t" + Time);
                break;


            case "News":
                string Time = valueRow.InnerText;
                Console.WriteLine("News:\t" + News);
                break;

            default:
                // put special time condition check logic here.
        }
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