Home

Conditional Selections

The Select...Case Statement

Introduction

If you have a large number of conditions to examine, the If...Then...Else statement will go through each one of them. The Visual Basic language offers the alternative of jumping to the statement that applies to the stated condition. This is done with the Select Case operator.

The formula of the Select Case statement is:

Select Case expression
    Case expression1
	statement1
    Case expression2
	statement2
    Case expressionX
	statementX
End Select

The statement starts with Select Case and ends with End Select. On the right side of Select Case, enter a value or an expression that will be checked.

The Type of Expression to Test

The value of expression can be Boolean value. In this case, one case would be True and the other would be False. Here is an example:

<!DOCTYPE html>

<html>
<head>
<script language="VB" runat="server">
Sub btnCreateRecordClick(ByVal sender As Object, ByVal e As EventArgs)
    dim unitPrice As Double
    dim markedPrice  As Double
    dim discountAmount As Double

    unitPrice = CDbl(txtUnitPrice.Text)

    Select Case chkApplyDiscount.Checked
        Case True
            discountAmount = unitPrice * 20.00 / 100.00

        Case False
            discountAmount = 0.00
    End Select

    markedPrice = unitPrice - discountAmount

    lblItemNumber.Text = txtItemNumber.Text
    lblItemName.Text = txtItemName.Text
    lblUnitPrice.Text = FormatNumber(markedPrice)
End Sub
</script>
<title>Department Store - Inventory Creation</title>
</head>
<body>
<div align="center">

<form id="frmStoreItem" runat="server">
<h3>Department Store - Inventory Creation</h3>

<table>
  <tr>
    <td>Item #:</td>
    <td><asp:TextBox id="txtItemNumber" text="000000" runat="server" /></td>
  </tr>
  <tr>
    <td>Item Name:</td>
    <td><asp:TextBox id="txtItemName" runat="server" /></td>
  </tr>

  <tr>
    <td>Unit Price:</td>
    <td><asp:TextBox id="txtUnitPrice" text="0.00" runat="server" /></td>
  </tr>
    <tr>
    <td><asp:CheckBox id="chkApplyDiscount" text="Apply 20% Discount"
                                   TextAlign="Left" runat="server" /></td>
    <td>&nbsp;</td>
  </tr>
    <tr>
    <td>&nbsp;</td>
    <td><asp:Button id="btnCreateRecord"
                              text="Create Record"
                              OnClick="btnCreateRecordClick"
                              runat="server"></asp:Button> </td>
  </tr>
</table>

<h3>Department Store - Store Inventory</h3>

<table>
  <tr>
    <td>Item #:</td>
    <td><asp:Label id="lblItemNumber" runat="server" /></td>
  </tr>
  <tr>
    <td>Item Name:</td>
    <td><asp:Label id="lblItemName" runat="server" /></td>
  </tr>
  <tr>
    <td>Unit Price:</td>
    <td><asp:Label id="lblUnitPrice" runat="server" /></td>
  </tr>
</table>

</form>
</div>
</body>
</html>

Here is an example of using the webpage:

The Type of Expression to Test

The Type of Expression to Test

The Type of Expression to Test

The Type of Expression to Test

The expression can produce a character (Char type) or a string (a String type). In this case, each Case would deal with a value in double-quotes. Here is an example:

<%@ Page Language="VB" %>

<!DOCTYPE html>

<html>
<head runat="server">
<script runat="server">
Sub ddlLinesSelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
    Select Case ddlLines.SelectedItem.Text
        Case "Red Line"
            pnlAllStations.Visible = False
            pnlOrangeLine.Visible = False
            pnlGreenLine.Visible = False
            pnlBlueLine.Visible = False
            pnlRedLine.Visible = True
        Case "Green Line"
            pnlAllStations.Visible = False
            pnlRedLine.Visible = False
            pnlOrangeLine.Visible = False
            pnlBlueLine.Visible = False
            pnlGreenLine.Visible = True
        Case "Blue Line"
            pnlAllStations.Visible = False
            pnlRedLine.Visible = False
            pnlOrangeLine.Visible = False
            pnlGreenLine.Visible = False
            pnlBlueLine.Visible = True
        Case "Orange Line"
            pnlAllStations.Visible = False
            pnlRedLine.Visible = False
            pnlBlueLine.Visible = False
            pnlGreenLine.Visible = False
            pnlOrangeLine.Visible = True
        Case "All Stations"
            pnlRedLine.Visible = False
            pnlBlueLine.Visible = False
            pnlOrangeLine.Visible = False
            pnlGreenLine.Visible = False
            pnlAllStations.Visible = True
    End Select
End Sub
</script>
<style type="text/css">
#main-title
{
    font-size: 1.28em;
    font-weight: bold;
    text-align: center;
    font-family: Georgia, Garamond, Times New Roman, Times, serif;
}
h2 { text-align: center; }
#tblMetroLineSelection { width: 390px; }
#whole
{
    margin: auto;
    width:  395px;
}
</style>
<title>Metro System</title>
</head>
<body>
<form id="frmMetroSystem" runat="server">
<div id="whole">

<p id="main-title">Metro System</p>

<table id="tblMetroLineSelection" align="center">
  <tr>
    <td>
       <asp:Label id="lblMetroLine" runat="server"
                  Text="Select the metro line:"></asp:Label>
    </td>
    <td>
       <asp:DropDownList id="ddlLines" runat="server"
                         AutoPostBack="True"
                         OnSelectedIndexChanged="ddlLinesSelectedIndexChanged">
         <asp:ListItem>Red Line</asp:ListItem>
         <asp:ListItem>Green Line</asp:ListItem>
         <asp:ListItem>Blue Line</asp:ListItem>
         <asp:ListItem>Orange Line</asp:ListItem>
         <asp:ListItem>All Stations</asp:ListItem>
      </asp:DropDownList>
    </td>
    </tr>
  </table>
  <asp:Panel id="pnlAllStations" runat="server" Visible="True">
    <h2>All Stations</h2>
    <table align="center"><tr><td>
    <asp:ListBox ID="lbxAllStations" Height="400px" style="margin: 0 auto" runat="server">
      <asp:ListItem>Shady Grove</asp:ListItem><asp:ListItem>Rockville</asp:ListItem>
      <asp:ListItem>Twinbrook</asp:ListItem><asp:ListItem>White Flint</asp:ListItem>
      <asp:ListItem>Grosvenor-Strathmore</asp:ListItem><asp:ListItem>Medical Center</asp:ListItem>
      <asp:ListItem>Bethesda</asp:ListItem><asp:ListItem>Friendship Heights</asp:ListItem>
      <asp:ListItem>Tenleytown-AU</asp:ListItem><asp:ListItem>Van Ness-UDC</asp:ListItem>
      <asp:ListItem>Greebelt</asp:ListItem><asp:ListItem>Cleveland Park</asp:ListItem>
      <asp:ListItem>Woodley Park-Zoo/Adams Morgan</asp:ListItem>
      <asp:ListItem>Dupont Circle</asp:ListItem><asp:ListItem>Farragut North</asp:ListItem>
      <asp:ListItem>Metro Center</asp:ListItem><asp:ListItem>Gallery Pl-Chinatown</asp:ListItem>
      <asp:ListItem>Judiciary Square</asp:ListItem><asp:ListItem>Union Station</asp:ListItem>
      <asp:ListItem>NoMa-Gallaudet U</asp:ListItem><asp:ListItem>New Carrolton</asp:ListItem>
      <asp:ListItem>Rhode Island Ave-Brentwood</asp:ListItem>
      <asp:ListItem>Brookland-CUA</asp:ListItem><asp:ListItem>Fort Totten</asp:ListItem>
      <asp:ListItem>Takoma</asp:ListItem><asp:ListItem>Silver Spring</asp:ListItem>
      <asp:ListItem>Forest Glen</asp:ListItem><asp:ListItem>Wheaton</asp:ListItem>
      <asp:ListItem>Glenmont</asp:ListItem><asp:ListItem>Franconia-Springfield</asp:ListItem>
    </asp:ListBox>
    </td></tr></table>
  </asp:Panel>

  <asp:Panel id="pnlRedLine" Visible="False" runat="server">
    <h2>Red Line</h2>
    <table align="center"><tr><td>
    <asp:ListBox ID="lbxRedLine" Height="300px" runat="server">
      <asp:ListItem>Shady Grove</asp:ListItem><asp:ListItem>Rockville</asp:ListItem>
      <asp:ListItem>Twinbrook</asp:ListItem><asp:ListItem>White Flint</asp:ListItem>
      <asp:ListItem>Grosvenor-Strathmore</asp:ListItem><asp:ListItem>Medical Center</asp:ListItem>
      <asp:ListItem>Bethesda</asp:ListItem><asp:ListItem>Friendship Heights</asp:ListItem>
      <asp:ListItem>Tenleytown-AU</asp:ListItem><asp:ListItem>Van Ness-UDC</asp:ListItem>
      <asp:ListItem>Cleveland Park</asp:ListItem>
      <asp:ListItem>Woodley Park-Zoo/Adams Morgan</asp:ListItem>
      <asp:ListItem>Dupont Circle</asp:ListItem><asp:ListItem>Farragut North</asp:ListItem>
      <asp:ListItem>Metro Center</asp:ListItem><asp:ListItem>Gallery Pl-Chinatown</asp:ListItem>
      <asp:ListItem>Judiciary Square</asp:ListItem><asp:ListItem>Union Station</asp:ListItem>
      <asp:ListItem>NoMa-Gallaudet U</asp:ListItem><asp:ListItem>Glenmont</asp:ListItem>
      <asp:ListItem>Rhode Island Ave-Brentwood</asp:ListItem>
      <asp:ListItem>Brookland-CUA</asp:ListItem><asp:ListItem>Fort Totten</asp:ListItem>
      <asp:ListItem>Takoma</asp:ListItem><asp:ListItem>Silver Spring</asp:ListItem>
      <asp:ListItem>Forest Glen</asp:ListItem><asp:ListItem>Wheaton</asp:ListItem>
    </asp:ListBox>
    </td></tr></table>
  </asp:Panel>

  <asp:Panel id="pnlOrangeLine" Visible="False" runat="server">
    <h2>Orange Line</h2>
    <table align="center"><tr><td>
    <asp:ListBox ID="lbxOrangeLine" Height="130px"  runat="server">
      <asp:ListItem>New Carrolton</asp:ListItem><asp:ListItem>Landover</asp:ListItem>
      <asp:ListItem>Stadium-Armory</asp:ListItem><asp:ListItem>Eastern Market</asp:ListItem>
      <asp:ListItem>Metro Center</asp:ListItem>
      <asp:ListItem>Rosslyn</asp:ListItem><asp:ListItem>Vienna</asp:ListItem>
    </asp:ListBox>
    </td></tr></table>
  </asp:Panel>

  <asp:Panel id="pnlGreenLine" Visible="False" runat="server">
    <h2>Green Line</h2>
    <table align="center"><tr><td>
    <asp:ListBox ID="lbxLineGreen" Height="105px"  runat="server">
      <asp:ListItem>Greenbelt</asp:ListItem><asp:ListItem>Fort Totten</asp:ListItem>
      <asp:ListItem>Gallery Pl-Chinatown</asp:ListItem><asp:ListItem>Archives</asp:ListItem>
      <asp:ListItem>Waterfront</asp:ListItem><asp:ListItem>Branch Ave</asp:ListItem>
    </asp:ListBox>
    </td></tr></table>
  </asp:Panel>

  <asp:Panel id="pnlBlueLine" Visible="False" runat="server">
    <h2>Blue Line</h2>
    <table align="center"><tr><td>
    <asp:ListBox ID="lbxBlueLine" Height="105px"  runat="server">
      <asp:ListItem>Largo Town Center</asp:ListItem><asp:ListItem>Stadium-Armory</asp:ListItem>
      <asp:ListItem>Eastern Market</asp:ListItem><asp:ListItem>Metro Center</asp:ListItem>
      <asp:ListItem>Rosslyn</asp:ListItem><asp:ListItem>Franconia-Springfield</asp:ListItem>
    </asp:ListBox>
    </td></tr></table>
  </asp:Panel>
</div>
</form>
</body>
</html>

The expression can produce an integer (a Byte, an SByte, a Short, a UShort, an Integer, a UInteger, a Long, or a ULongtype). In this case, each Case would deal with one of the numeric outcomes. Here is an example:

<%@ Page Language="VB" %>

<!DOCTYPE html>

<html>
<head runat="server">
<style type="text/css">
#tblPreparation { width: 450px; }
#tblEvaluation { width: 300px; }

#pre-section
{
    margin: auto;
    width:  455px;
}

#eval-section
{
    margin: auto;
    width:  255px;
}

.main-title
{
    font-size:     0.65cm;
    font-weight: bold;
    text-align:    center;
    font-family:  Garamond, Georgia, Times New Roman, serif;
}
</style>

<script runat="server">
Sub btnCalculateClick(ByVal sender As Object, ByVal e As EventArgs)
    Dim incomeTax As Double
    Dim hourlySalary As Double, timeWorked As Double
    Dim grossSalary As Double, netPay As Double
    Dim payrollFrequency  As Integer

    hourlySalary = CDbl(TxtHourlySalary.Text)
    timeWorked = CDbl(TxtTimeWorked.Text)

    grossSalary = hourlySalary * timeWorked

    payrollFrequency = RblPayrollFrequency.SelectedIndex

    Select Case payrollFrequency
        Case 0
            incomeTax = 99.1 + (grossSalary * 0.25)
        Case 1
            incomeTax = 35.5 + (grossSalary * 0.15)
        Case 2
            incomeTax = 38.4 + (grossSalary * 0.15)
        Case 3
            incomeTax = 76.8 + (grossSalary * 0.15)
    End Select

    netPay = grossSalary - incomeTax

    LblEmployeeName.Text = TxtEmployeeName.Text
    LblHourlySalary.Text = TxtHourlySalary.Text
    LblTimeWorked.Text = TxtTimeWorked.Text
    LblGrossSalary.Text = formatnumber(grossSalary)

    Select Case payrollFrequency
        Case 0
            LblPayrollFrequency.Text = "Weekly"
        Case 1
            LblPayrollFrequency.Text = "Biweekly"
        Case 2
            LblPayrollFrequency.Text = "Semimonthly"
        Case 3
            LblPayrollFrequency.Text = "Monthly"
    End Select

    LblIncomeTax.Text = formatnumber(incomeTax)
    LblNetPay.Text = formatnumber(netPay)

    PnlPreparation.Visible = False
    PnlEvaluation.Visible = True
End Sub
</script>

<title>Payroll Preparation</title>
</head>
<body>
<form id="frmPayroll" runat="server">
<div id="pre-section">

<asp:Panel id="PnlPreparation" runat="server">

<p class="main-title">Payroll Preparation</p>

<table id="tblPreparation">
  <tr>
    <td><p><b>Employee Time Sheet</b></p>
      <table>
        <tr>
          <td style="width: 160px;">Employee Name:</td>
          <td>
            <asp:TextBox id="TxtEmployeeName"
                         runat="server"></asp:TextBox>
          </td>
        </tr>
        <tr>
          <td>Hourly Salary:</td>
          <td>
            <asp:TextBox id="TxtHourlySalary" runat="server"
                                 Width="50px">0.00</asp:TextBox>
          </td>
        </tr>
        <tr>
          <td>Time Worked:</td>
          <td>
            <asp:TextBox id="TxtTimeWorked" runat="server"
                                 Width="50px">0.00</asp:TextBox>
          </td>
        </tr>
        <tr>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
        </tr>
      </table>
    </td>
    <td style="width: 140px;"><p><b>Payroll Frequency</b></p>
      <asp:RadioButtonList id="RblPayrollFrequency" runat="server">
        <asp:ListItem>Weekly</asp:ListItem>
        <asp:ListItem>Biweekly</asp:ListItem>
        <asp:ListItem>Semimonthly</asp:ListItem>
        <asp:ListItem>Monthly</asp:ListItem>
      </asp:RadioButtonList>
    </td>
  </tr>
  <tr>
    <td colspan="2">
      <p style="text-align: center">
        <asp:Button id="BtnCalculate" runat="server" style="height: 32px;"
                    Text="Calculate" Width="182px" OnClick="BtnCalculateClick" /></p>
    </td>
    </tr>
  </table>
</asp:Panel>
</div>

<div id="eval-section">
<asp:Panel id="PnlEvaluation" Visible="False" runat="server">

  <p class="main-title">Payroll Evaluation</p>

  <table id="tblEvaluation" border=5>
    <tr>
      <td>Employee Name:</td>
      <td><asp:Label id="LblEmployeeName"
                                  runat="server"></asp:Label></td>
    </tr>
    <tr>
      <td>Hourly Salary:</td>
      <td><asp:Label id="LblHourlySalary" runat="server"
                       Width="75px">0.00</asp:Label></td>
    </tr>
    <tr>
      <td>Time Worked:</td>
      <td><asp:Label id="LblTimeWorked"
                       runat="server" Width="75px">0.00</asp:Label></td>
    </tr>
    <tr>
      <td>Gross Salary:</td>
      <td><asp:Label id="LblGrossSalary"
                       runat="server" Width="75px">0.00</asp:Label></td>
    </tr>
    <tr>
      <td>Payroll Frequency:</td>
      <td><asp:Label id="LblPayrollFrequency"
                       runat="server" Width="75px">0</asp:Label></td>
    </tr>
    <tr>
      <td>Income Tax:</td>
      <td><asp:Label id="LblIncomeTax" runat="server"
                       Width="75px">0.00</asp:Label>
      </td>
    </tr>
    <tr>
      <td>Net Pay:</td>
      <td><asp:Label id="LblNetPay" runat="server"
                       Width="75px">0.00</asp:Label></td>
    </tr>
  </table>
</asp:Panel>

</div>
</form>
</body>
</html>

Here is an example of using the webpage:

The Type of Expression to Test

The Type of Expression to Test

The Type of Expression to Test

The expression can be an enumeration. In this case, the expression would be the name of the enumeration. Each Case would deal with one of the members of the enumeration.

What Case Else?

If you anticipate that there could be no match between the expression and one of the values in the cases, you can use a Case Else statement at the end of the list. The statement would then look like this:

Select Case expression
    Case expression1
	statement1
    Case expression2
	statement2
    . . .

    Case expression-n
	statement-n
    Case Else
	statement-else
End Select

In this case, the statement after the Case Else will execute if none of the values of the cases matches the expression.

Combining Cases

When creating a Select Case situation, you may end up using two or more cases that proceed to the same outcome. Here is an example:

<%@ Page Language="VB" %>

<!DOCTYPE html>

<html>
<head runat="server">
<script runat="server">
Sub btnFindClick(ByVal sender As Object, ByVal e As EventArgs)
    Select Case txtMetroLine.Text
        Case "R"
            pnlAllStations.Visible = False
            pnlOrangeLine.Visible = False
            pnlGreenLine.Visible = False
            pnlBlueLine.Visible = False
            pnlRedLine.Visible = True
        Case "Green"
            pnlAllStations.Visible = False
            pnlRedLine.Visible = False
            pnlOrangeLine.Visible = False
            pnlBlueLine.Visible = False
            pnlGreenLine.Visible = True
        Case "Blue"
            pnlAllStations.Visible = False
            pnlRedLine.Visible = False
            pnlOrangeLine.Visible = False
            pnlGreenLine.Visible = False
            pnlBlueLine.Visible = True
        Case "Red"
            pnlAllStations.Visible = False
            pnlOrangeLine.Visible = False
            pnlGreenLine.Visible = False
            pnlBlueLine.Visible = False
            pnlRedLine.Visible = True
        Case "G"
            pnlAllStations.Visible = False
            pnlRedLine.Visible = False
            pnlOrangeLine.Visible = False
            pnlBlueLine.Visible = False
            pnlGreenLine.Visible = True
        Case "Orange"
            pnlAllStations.Visible = False
            pnlRedLine.Visible = False
            pnlBlueLine.Visible = False
            pnlGreenLine.Visible = False
            pnlOrangeLine.Visible = True
        Case "B"
            pnlAllStations.Visible = False
            pnlRedLine.Visible = False
            pnlOrangeLine.Visible = False
            pnlGreenLine.Visible = False
            pnlBlueLine.Visible = True
        Case Else
            ' "All Stations"
            pnlRedLine.Visible = False
            pnlBlueLine.Visible = False
            pnlOrangeLine.Visible = False
            pnlGreenLine.Visible = False
            pnlAllStations.Visible = True
    End Select
End Sub
</script>
<style type="text/css">
#main-title
{
    font-size: 1.28em;
    font-weight: bold;
    text-align: center;
    font-family: Georgia, Garamond, Times New Roman, Times, serif;
}
h2 { text-align: center; }
#tblMetroLineSelection { width: 390px; }
#whole
{
    margin: auto;
    width:  395px;
}
</style>
<title>Metro System</title>
</head>
<body>
<form id="frmMetroSystem" runat="server">
<div id="whole">

<p id="main-title">Metro System</p>

<table id="tblMetroLineSelection" align="center">
  <tr>
    <td>
       <asp:Label id="lblLineLetter" runat="server"
                  Text="Type the color (Red, Green, etc) of a metro line or simply enter its line letter (R, G, B, etc) or type :"></asp:Label>
    </td>
  </tr>
  <tr>
    <td>
       <asp:TextBox id="txtMetroLine" runat="server"></asp:TextBox>
       <asp:Button id="btnFind" Text="Find Metro Stations"
                   OnClick="btnFindClick" runat="server"></asp:Button>
    </td>
    </tr>
  </table>
  <asp:Panel id="pnlAllStations" runat="server" Visible="True">
    <h2>All Stations</h2>
    <table align="center"><tr><td>
    <asp:ListBox ID="lbxAllStations" Height="400px" style="margin: 0 auto" runat="server">
      <asp:ListItem>Shady Grove</asp:ListItem><asp:ListItem>Rockville</asp:ListItem>
      <asp:ListItem>Twinbrook</asp:ListItem><asp:ListItem>White Flint</asp:ListItem>
      <asp:ListItem>Grosvenor-Strathmore</asp:ListItem><asp:ListItem>Medical Center</asp:ListItem>
      <asp:ListItem>Bethesda</asp:ListItem><asp:ListItem>Friendship Heights</asp:ListItem>
      <asp:ListItem>Tenleytown-AU</asp:ListItem><asp:ListItem>Van Ness-UDC</asp:ListItem>
      <asp:ListItem>Greebelt</asp:ListItem><asp:ListItem>Cleveland Park</asp:ListItem>
      <asp:ListItem>Woodley Park-Zoo/Adams Morgan</asp:ListItem>
      <asp:ListItem>Dupont Circle</asp:ListItem><asp:ListItem>Farragut North</asp:ListItem>
      <asp:ListItem>Metro Center</asp:ListItem><asp:ListItem>Gallery Pl-Chinatown</asp:ListItem>
      <asp:ListItem>Judiciary Square</asp:ListItem><asp:ListItem>Union Station</asp:ListItem>
      <asp:ListItem>NoMa-Gallaudet U</asp:ListItem><asp:ListItem>New Carrolton</asp:ListItem>
      <asp:ListItem>Rhode Island Ave-Brentwood</asp:ListItem>
      <asp:ListItem>Brookland-CUA</asp:ListItem><asp:ListItem>Fort Totten</asp:ListItem>
      <asp:ListItem>Takoma</asp:ListItem><asp:ListItem>Silver Spring</asp:ListItem>
      <asp:ListItem>Forest Glen</asp:ListItem><asp:ListItem>Wheaton</asp:ListItem>
      <asp:ListItem>Glenmont</asp:ListItem><asp:ListItem>Franconia-Springfield</asp:ListItem>
    </asp:ListBox>
    </td></tr></table>
  </asp:Panel>

  <asp:Panel id="pnlRedLine" Visible="False" runat="server">
    <h2>Red Line</h2>
    <table align="center"><tr><td>
    <asp:ListBox ID="lbxRedLine" Height="300px" runat="server">
      <asp:ListItem>Shady Grove</asp:ListItem><asp:ListItem>Rockville</asp:ListItem>
      <asp:ListItem>Twinbrook</asp:ListItem><asp:ListItem>White Flint</asp:ListItem>
      <asp:ListItem>Grosvenor-Strathmore</asp:ListItem><asp:ListItem>Medical Center</asp:ListItem>
      <asp:ListItem>Bethesda</asp:ListItem><asp:ListItem>Friendship Heights</asp:ListItem>
      <asp:ListItem>Tenleytown-AU</asp:ListItem><asp:ListItem>Van Ness-UDC</asp:ListItem>
      <asp:ListItem>Cleveland Park</asp:ListItem>
      <asp:ListItem>Woodley Park-Zoo/Adams Morgan</asp:ListItem>
      <asp:ListItem>Dupont Circle</asp:ListItem><asp:ListItem>Farragut North</asp:ListItem>
      <asp:ListItem>Metro Center</asp:ListItem><asp:ListItem>Gallery Pl-Chinatown</asp:ListItem>
      <asp:ListItem>Judiciary Square</asp:ListItem><asp:ListItem>Union Station</asp:ListItem>
      <asp:ListItem>NoMa-Gallaudet U</asp:ListItem><asp:ListItem>Glenmont</asp:ListItem>
      <asp:ListItem>Rhode Island Ave-Brentwood</asp:ListItem>
      <asp:ListItem>Brookland-CUA</asp:ListItem><asp:ListItem>Fort Totten</asp:ListItem>
      <asp:ListItem>Takoma</asp:ListItem><asp:ListItem>Silver Spring</asp:ListItem>
      <asp:ListItem>Forest Glen</asp:ListItem><asp:ListItem>Wheaton</asp:ListItem>
    </asp:ListBox>
    </td></tr></table>
  </asp:Panel>

  <asp:Panel id="pnlOrangeLine" Visible="False" runat="server">
    <h2>Orange Line</h2>
    <table align="center"><tr><td>
    <asp:ListBox ID="lbxOrangeLine" Height="130px"  runat="server">
      <asp:ListItem>New Carrolton</asp:ListItem><asp:ListItem>Landover</asp:ListItem>
      <asp:ListItem>Stadium-Armory</asp:ListItem><asp:ListItem>Eastern Market</asp:ListItem>
      <asp:ListItem>Metro Center</asp:ListItem>
      <asp:ListItem>Rosslyn</asp:ListItem><asp:ListItem>Vienna</asp:ListItem>
    </asp:ListBox>
    </td></tr></table>
  </asp:Panel>

  <asp:Panel id="pnlGreenLine" Visible="False" runat="server">
    <h2>Green Line</h2>
    <table align="center"><tr><td>
    <asp:ListBox ID="lbxLineGreen" Height="105px"  runat="server">
      <asp:ListItem>Greenbelt</asp:ListItem><asp:ListItem>Fort Totten</asp:ListItem>
      <asp:ListItem>Gallery Pl-Chinatown</asp:ListItem><asp:ListItem>Archives</asp:ListItem>
      <asp:ListItem>Waterfront</asp:ListItem><asp:ListItem>Branch Ave</asp:ListItem>
    </asp:ListBox>
    </td></tr></table>
  </asp:Panel>

  <asp:Panel id="pnlBlueLine" Visible="False" runat="server">
    <h2>Blue Line</h2>
    <table align="center"><tr><td>
    <asp:ListBox ID="lbxBlueLine" Height="105px"  runat="server">
      <asp:ListItem>Largo Town Center</asp:ListItem><asp:ListItem>Stadium-Armory</asp:ListItem>
      <asp:ListItem>Eastern Market</asp:ListItem><asp:ListItem>Metro Center</asp:ListItem>
      <asp:ListItem>Rosslyn</asp:ListItem><asp:ListItem>Franconia-Springfield</asp:ListItem>
    </asp:ListBox>
    </td></tr></table>
  </asp:Panel>
</div>
</form>
</body>
</html>

Here is an example of using the webpage:

The Type of Expression to Test

The Type of Expression to Test

The Type of Expression to Test

If you have different values for cases and those values are similar outcomes, you can combine those cases. To do this, on the right side of the Case keyword, type each but separate them with commas. Here are examples:

<script runat="server">
Sub btnFindClick(ByVal sender As Object, ByVal e As EventArgs)
    Select Case txtMetroLine.Text
        Case "R",  "Red"
            pnlAllStations.Visible = False
            pnlOrangeLine.Visible = False
            pnlGreenLine.Visible = False
            pnlBlueLine.Visible = False
            pnlRedLine.Visible = True
        Case "G", "Green"
            pnlAllStations.Visible = False
            pnlRedLine.Visible = False
            pnlOrangeLine.Visible = False
            pnlBlueLine.Visible = False
            pnlGreenLine.Visible = True
        Case "B", "Blue"
            pnlAllStations.Visible = False
            pnlRedLine.Visible = False
            pnlOrangeLine.Visible = False
            pnlGreenLine.Visible = False
            pnlBlueLine.Visible = True
        Case "O", "Orange"
            pnlAllStations.Visible = False
            pnlRedLine.Visible = False
            pnlBlueLine.Visible = False
            pnlGreenLine.Visible = False
            pnlOrangeLine.Visible = True
        Case Else
            ' "All Stations"
            pnlRedLine.Visible = False
            pnlBlueLine.Visible = False
            pnlOrangeLine.Visible = False
            pnlGreenLine.Visible = False
            pnlAllStations.Visible = True
    End Select
End Sub
</script>

Applying a Range of Values for a Case

You can use a range of values for a case. To do this, on the right side of Case, enter the lower value, followed by To, followed by the higher value. Here is an example:

<script runat="server">
Sub Find()
    Dim nbr As Integer
    nbr = 24

    Select Case nbr
        Case 0 To 17
            Response.Write("Teen")
        Case 18 To 55
            Response.Write("Adult")
    
        Case Else
            Response.Write("Senior")
        End Select
    End Sub

End Sub
</script>

Checking Whether a Case Value IS

Instead of specifying the exact value for a case, you can check whether the value of the expression responds to a Boolean expression instead of an exact value. To create it, you use the Is keyword with the following formula:

Is operator value

You start with the Is keyword. It is followed by a Boolean operator (=, <>, <, <=, >, or >=). On the right side of the boolean operator, type the desired value. Here are examples:

<script runat="server">
Sub Find()
    Dim Number As Short

    Number = -448

    Select Case Number
        Case Is < 0
          Response.Write("The number is negative")
        Case Is > 0
          Response.Write("The number is positive")

        Case Else
          Response.Write("0",
	       	       MsgBoxStyle.OkOnly Or MsgBoxStyle.Information,
	       	       "Conditional Selections")
    End Select
End Sub
</script>

Although we used a natural number here, you can use any appropriate logical comparison that can produce a True or a False result. You can also combine it with the other alternatives we saw previously, such as separating the expressions of a case with commas.

Select...Case and Conditional Built-In Functions

To functionaly apply select cases, the Visual Basic language provides a function named Choose that can check a condition and take an action. The Choose() function is presented as follows:

Function Choose(ByVal Index As Double,
		     many parameters) As Object

This function takes two required arguments. The first argument is equivalent to the expression of our Select Case formula. The first argument must be a number (a Byte, an SByte, a Short, UShort, an Integer, a UInteger, a Long, a ULong, a Single, a Double, or a Decimal value). In place of the Case sections, for the second argument, provide the equivalent expression-x as a list of values. The values are separated by commas. Here is an example:

Choose(Number, "Teen", "Adult", "Senior")

As mentioned already, the values of the second argument are provided as a list. Each member of the list uses an index. The first member of the list, which is the second argument of this function, has an index of 1. The second value of the argument, which would be the third argument of the function, has an index of 2. You can continue adding the values of the second argument as you see fit.

When the Choose() function has been called, it returns a value of type Object. You can retrieve that value, store it in a variable and use it as you see fit.

 
 
 

Options on Using Conditional Selections

Nesting a Conditional Statement

A conditional statement can be created in the body of a Case statement. In fact, a Select statement can be created in a Case or a Case Else section. This is referred to as nesting.

Conditional Selections and Conditional Statements

A conditional statement can be created or nested in a case of a conditional selection. Here are examples of nesting If...ElseIf...Else conditional statements in Select Cases:

<%@ Page Language="VB" %>

<!DOCTYPE html>

<html>
<head runat="server">
<script runat="server">
Sub btnCalculateClick(ByVal sender As Object, ByVal e As EventArgs)
    Dim withheldAmount As Double
    Dim allowanceRate As Double
    Dim salary As Double
    Dim exemptions As Double
    Dim withholdingAllowances As Double
    Dim taxableGrossWages As Double

    allowanceRate = 76.9
    salary = CDbl(txtSalary.Text)
    exemptions = CDbl(txtExemptions.Text)

    withholdingAllowances = allowanceRate * exemptions
    taxableGrossWages = salary - withholdingAllowances

    Select Case ddlMaritalsStatus.SelectedItem.Text
        Case "Single"
            If taxableGrossWages <= 44.0 Then
                withheldAmount = 0.0
            ElseIf (taxableGrossWages > 44.0) And (taxableGrossWages <= 222.0) Then
                withheldAmount = (taxableGrossWages - 44.0) * 10.0 / 100.0
            ElseIf (taxableGrossWages > 222.0) And (taxableGrossWages <= 764.0) Then
                withheldAmount = 17.8 + ((taxableGrossWages - 222.0) * 15.0 / 100.0)
            ElseIf (taxableGrossWages > 764.0) And (taxableGrossWages <= 1789.0) Then
                withheldAmount = 99.1 + ((taxableGrossWages - 764.0) * 25.0 / 100.0)
            ElseIf (taxableGrossWages > 1789.0) And (taxableGrossWages <= 3685.0) Then
                withheldAmount = 355.05 + ((taxableGrossWages - 1789.0) * 28.0 / 100.0)
            ElseIf (taxableGrossWages > 3685.0) And (taxableGrossWages <= 7958.0) Then
                withheldAmount = 886.23 + ((taxableGrossWages - 3685.0) * 33.0 / 100.0)
            ElseIf (taxableGrossWages > 7958.0) And (taxableGrossWages <= 7990.0) Then
                withheldAmount = 2296.32 + ((taxableGrossWages - 7958.0) * 35.0 / 100.0)
            Else
                withheldAmount = 2307.52 + ((taxableGrossWages - 7990.0) * 39.6 / 100.0)
            End If
        Case "Married"
            If taxableGrossWages <= 165.0 Then
                withheldAmount = 0.0
            ElseIf (taxableGrossWages > 165.0) And (taxableGrossWages <= 520.0) Then
                withheldAmount = (taxableGrossWages - 165.0) * 10.0 / 100.0
            ElseIf (taxableGrossWages > 520.0) And (taxableGrossWages <= 1606.0) Then
                withheldAmount = 35.5 + ((taxableGrossWages - 520.0) * 15.0 / 100.0)
            ElseIf (taxableGrossWages > 1606.0) And (taxableGrossWages <= 3073.0) Then
                withheldAmount = 198.4 + ((taxableGrossWages - 1606.0) * 25.0 / 100.0)
            ElseIf (taxableGrossWages > 3073.0) And (taxableGrossWages <= 4597.0) Then
                withheldAmount = 565.15 + ((taxableGrossWages - 3073.0) * 28.0 / 100.0)
            ElseIf (taxableGrossWages > 4597.0) And (taxableGrossWages <= 8079.0) Then
                withheldAmount = 991.87 + ((taxableGrossWages - 4597.0) * 33.0 / 100.0)
            ElseIf (taxableGrossWages > 8079.0) And (taxableGrossWages <= 9105.0) Then
                withheldAmount = 2140.93 + ((taxableGrossWages - 8079.0) * 35.0 / 100.0)
            Else
                withheldAmount = 2500.03 + ((taxableGrossWages - 9105.0) * 39.6 / 100.0)
            End If
    End Select

    txtAllowances.Text = FormatNumber(withholdingAllowances)
    txtTaxableGrossWages.Text = FormatNumber(taxableGrossWages)
    txtFederalIncomeTax.Text = FormatNumber(withheldAmount)
End Sub
</script>
<title>Federal Withholding Tax</title>
</head>
<body>
<form id="frmWithholding" runat="server">
<div align="center">

<h3>Federal Withholding Tax</h3>

<table>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblMaritalStatus" runat="server" Text="Marital Status:" /></td>
    <td style="text-align: left">
          <asp:DropDownList id="ddlMaritalsStatus" Width="90px" runat="server">
          <asp:ListItem>Single</asp:ListItem>
          <asp:ListItem>Married</asp:ListItem>
        </asp:DropDownList></td>
  </tr>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblSalary" runat="server" Text="Salary:" />
      </td>
    <td style="text-align: left">
        <asp:TextBox id="txtSalary" Width="85px"
                                text="0.00" runat="server" /></td>
  </tr>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblExemptions" runat="server" Text="Exemptions:" /></td>
    <td style="text-align: left">
        <asp:TextBox id="txtExemptions" Width="85px" Text="0" runat="server"></asp:TextBox>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td style="text-align: left">
        <asp:Button id="btnCalculate" Width="90px"
                              text="Calculate"
                              runat="server" OnClick="btnCalculateClick"></asp:Button></td>
  </tr>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblAllowances" runat="server" Text="Allowances:" />
      </td>
    <td style="text-align: left">
        <asp:TextBox id="txtAllowances" Width="85px"
                             text="0.00" runat="server" /></td>
  </tr>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblTaxableGrossWages" runat="server" Text="Taxable Gross Wages:" />
      </td>
    <td style="text-align: left">
        <asp:TextBox id="txtTaxableGrossWages" Width="85px"
                             text="0.00" runat="server" /></td>
  </tr>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblFederalIncomeTax" runat="server" Text="Federal Income Tax:" />
      </td>
    <td style="text-align: left">
        <asp:TextBox id="txtFederalIncomeTax" Width="85px"
                             text="0.00" runat="server" /></td>
  </tr>
  </table>
</div>
</form>
</body>
</html>

Here is an example of using the webpage:

Conditional Selections and Conditional Statements

Conditional Selections and Conditional Statements

Conditional Selections and Conditional Statements

Conditional Selections and Conditional Statements

In the same way, you can nest a conditional statement that itself is nested in a matching pattern that itself is nested in another conditional statement or in another matching pattern, etc. Here is an example:

<%@ Page Language="VB" %>

<!DOCTYPE html>

<html>
<head runat="server">
<script runat="server">
Sub btnCalculateClick(ByVal sender As Object, ByVal e As EventArgs)
    Dim withheldAmount As Double
    Dim allowanceRate As Double
    Dim salary As Double
    Dim exemptions As Double
    Dim withholdingAllowances As Double
    Dim taxableGrossWages As Double

    allowanceRate = 76.9
    salary = CDbl(txtSalary.Text)
    exemptions = CDbl(txtExemptions.Text)

    withholdingAllowances = allowanceRate * exemptions
    taxableGrossWages = salary - withholdingAllowances

    Select Case ddlPayrollFrequency.SelectedItem.Text
        Case "Weekly"
            Select Case ddlMaritalsStatus.SelectedItem.Text
                Case "Single"
                    If taxableGrossWages <= 44.0 Then
                        withheldAmount = 0.0
                    ElseIf (taxableGrossWages > 44.0) And (taxableGrossWages <= 222.0) Then
                        withheldAmount = (taxableGrossWages - 44.0) * 10.0 / 100.0
                    ElseIf (taxableGrossWages > 222.0) And (taxableGrossWages <= 764.0) Then
                        withheldAmount = 17.8 + ((taxableGrossWages - 222.0) * 15.0 / 100.0)
                    ElseIf (taxableGrossWages > 764.0) And (taxableGrossWages <= 1789.0) Then
                        withheldAmount = 99.1 + ((taxableGrossWages - 764.0) * 25.0 / 100.0)
                    ElseIf (taxableGrossWages > 1789.0) And (taxableGrossWages <= 3685.0) Then
                        withheldAmount = 355.05 + ((taxableGrossWages - 1789.0) * 28.0 / 100.0)
                    ElseIf (taxableGrossWages > 3685.0) And (taxableGrossWages <= 7958.0) Then
                        withheldAmount = 886.23 + ((taxableGrossWages - 3685.0) * 33.0 / 100.0)
                    ElseIf (taxableGrossWages > 7958.0) And (taxableGrossWages <= 7990.0) Then
                        withheldAmount = 2296.32 + ((taxableGrossWages - 7958.0) * 35.0 / 100.0)
                    Else
                        withheldAmount = 2307.52 + ((taxableGrossWages - 7990.0) * 39.6 / 100.0)
                    End If
                Case "Married"
                    If taxableGrossWages <= 165.0 Then
                        withheldAmount = 0.0
                    ElseIf (taxableGrossWages > 165.0) And (taxableGrossWages <= 520.0) Then
                        withheldAmount = (taxableGrossWages - 165.0) * 10.0 / 100.0
                    ElseIf (taxableGrossWages > 520.0) And (taxableGrossWages <= 1606.0) Then
                        withheldAmount = 35.5 + ((taxableGrossWages - 520.0) * 15.0 / 100.0)
                    ElseIf (taxableGrossWages > 1606.0) And (taxableGrossWages <= 3073.0) Then
                        withheldAmount = 198.4 + ((taxableGrossWages - 1606.0) * 25.0 / 100.0)
                    ElseIf (taxableGrossWages > 3073.0) And (taxableGrossWages <= 4597.0) Then
                        withheldAmount = 565.15 + ((taxableGrossWages - 3073.0) * 28.0 / 100.0)
                    ElseIf (taxableGrossWages > 4597.0) And (taxableGrossWages <= 8079.0) Then
                        withheldAmount = 991.87 + ((taxableGrossWages - 4597.0) * 33.0 / 100.0)
                    ElseIf (taxableGrossWages > 8079.0) And (taxableGrossWages <= 9105.0) Then
                        withheldAmount = 2140.93 + ((taxableGrossWages - 8079.0) * 35.0 / 100.0)
                    Else
                        withheldAmount = 2500.03 + ((taxableGrossWages - 9105.0) * 39.6 / 100.0)
                    End If
            End Select

        Case "Biweekly"
            Select Case ddlMaritalsStatus.SelectedItem.Text
                Case "Single"
                    If taxableGrossWages <= 88.0 Then
                        withheldAmount = 0.0
                    ElseIf (taxableGrossWages > 88.0) And (taxableGrossWages <= 443.0) Then
                        withheldAmount = (taxableGrossWages - 88.0) * 10.0 / 100.0
                    ElseIf (taxableGrossWages > 443.0) And (taxableGrossWages <= 1529.0) Then
                        withheldAmount = 35.5 + ((taxableGrossWages - 443.0) * 15.0 / 100.0)
                    ElseIf (taxableGrossWages > 1529.0) And (taxableGrossWages <= 3579.0) Then
                        withheldAmount = 198.4 + ((taxableGrossWages - 1529.0) * 25.0 / 100.0)
                    ElseIf (taxableGrossWages > 3579.0) And (taxableGrossWages <= 7369.0) Then
                        withheldAmount = 710.9 + ((taxableGrossWages - 3579.0) * 28.0 / 100.0)
                    ElseIf (taxableGrossWages > 7369.0) And (taxableGrossWages <= 15915.0) Then
                        withheldAmount = 1772.1 + ((taxableGrossWages - 7369.0) * 33.0 / 100.0)
                    ElseIf (taxableGrossWages > 15915.0) And (taxableGrossWages <= 15981.0) Then
                        withheldAmount = 4592.28 + ((taxableGrossWages - 15915.0) * 35.0 / 100.0)
                    Else
                        withheldAmount = 4615.38 + ((taxableGrossWages - 15981.0) * 39.6 / 100.0)
                    End If
                Case "Married"
                    If taxableGrossWages <= 331.0 Then
                        withheldAmount = 0.0
                    ElseIf (taxableGrossWages > 331.0) And (taxableGrossWages <= 1040.0) Then
                        withheldAmount = (taxableGrossWages - 331.0) * 10.0 / 100.0
                    ElseIf (taxableGrossWages > 1040.0) And (taxableGrossWages <= 3212.0) Then
                        withheldAmount = 70.9 + ((taxableGrossWages - 1040.0) * 15.0 / 100.0)
                    ElseIf (taxableGrossWages > 3212.0) And (taxableGrossWages <= 6146.0) Then
                        withheldAmount = 396.7 + ((taxableGrossWages - 3212.0) * 25.0 / 100.0)
                    ElseIf (taxableGrossWages > 6146.0) And (taxableGrossWages <= 9194.0) Then
                        withheldAmount = 1130.2 + ((taxableGrossWages - 6146.0) * 28.0 / 100.0)
                    ElseIf (taxableGrossWages > 9194.0) And (taxableGrossWages <= 16158.0) Then
                        withheldAmount = 1983.64 + ((taxableGrossWages - 9194.0) * 33.0 / 100.0)
                    ElseIf (taxableGrossWages > 16158.0) And (taxableGrossWages <= 18210.0) Then
                        withheldAmount = 4281.76 + ((taxableGrossWages - 16158.0) * 35.0 / 100.0)
                    Else
                        withheldAmount = 4999.96 + ((taxableGrossWages - 18210.0) * 39.6 / 100.0)
                    End If
            End Select
    End Select

    txtAllowances.Text = FormatNumber(withholdingAllowances)
    txtTaxableGrossWages.Text = FormatNumber(taxableGrossWages)
    txtFederalIncomeTax.Text = FormatNumber(withheldAmount)
End Sub
</script>
<title>Federal Withholding Tax</title>
</head>
<body>
<form id="frmWithholding" runat="server">
<div align="center">

<h3>Federal Withholding Tax</h3>

<table>
  <tr>
    <td style="text-align: left">
        Payroll Frequency:</td>
    <td style="text-align: left">
          <asp:DropDownList id="ddlPayrollFrequency" Width="90px" runat="server">
          <asp:ListItem>Weekly</asp:ListItem>
          <asp:ListItem>Biweekly</asp:ListItem>
        </asp:DropDownList></td>
  </tr>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblMaritalStatus" runat="server" Text="Marital Status:" /></td>
    <td style="text-align: left">
          <asp:DropDownList id="ddlMaritalsStatus" Width="90px" runat="server">
          <asp:ListItem>Single</asp:ListItem>
          <asp:ListItem>Married</asp:ListItem>
        </asp:DropDownList></td>
  </tr>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblSalary" runat="server" Text="Salary:" />
      </td>
    <td style="text-align: left">
        <asp:TextBox id="txtSalary" Width="85px"
                                text="0.00" runat="server" /></td>
  </tr>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblExemptions" runat="server" Text="Exemptions:" /></td>
    <td style="text-align: left">
        <asp:TextBox id="txtExemptions" Width="85px" Text="0" runat="server"></asp:TextBox>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td style="text-align: left">
        <asp:Button id="btnCalculate" Width="90px"
                              text="Calculate"
                              runat="server" OnClick="btnCalculateClick"></asp:Button></td>
  </tr>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblAllowances" runat="server" Text="Allowances:" />
      </td>
    <td style="text-align: left">
        <asp:TextBox id="txtAllowances" Width="85px"
                             text="0.00" runat="server" /></td>
  </tr>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblTaxableGrossWages" runat="server" Text="Taxable Gross Wages:" />
      </td>
    <td style="text-align: left">
        <asp:TextBox id="txtTaxableGrossWages" Width="85px"
                             text="0.00" runat="server" /></td>
  </tr>
  <tr>
    <td style="text-align: left">
        <asp:Label id="lblFederalIncomeTax" runat="server" Text="Federal Income Tax:" />
      </td>
    <td style="text-align: left">
        <asp:TextBox id="txtFederalIncomeTax" Width="85px"
                             text="0.00" runat="server" /></td>
  </tr>
  </table>
</div>
</form>
</body>
</html>

Here is an example of using the webpage:

Conditional Selections and Conditional Statements

Conditional Selections and Conditional Statements

Conditional Selections and Conditional Statements

Conditional Selections and Conditional Statements

 
 
   
 

Previous Copyright © 2008-2016, FunctionX Next