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Conditionals Part 1 : If and Select Statements, How

     There are two types of conditional logic in ASP: if and select. I will show you how to use both of them. In Conditionals Part 2, I will discuss when and why to use each of them.

     An if statement is used to help a programmer determine whether to execute one set of code or another. The syntax for an if statement is the following:

If (condition) Then
    'some code
    'some other code
End If


If Num1 > Num2 Then
    Response.Write("Num1 is larger than num2...")
    Response.Write("Num2 is larger than num1...")
End If

     If statements can also be nested (put inside each other). An example of this is:

If Num1 > Num2 Then
    If num3 > num1 Then
        Response.Write("Num3 is larger than num1 and num2...")
        Response.Write("Num3 is smaller than num1...")
    End If
    If num3 > num2 Then
        Response.Write("Num3 is larger than num2 and num1...")
        Response.Write("Num3 is smaller than num2...")
    End If
End If

     Sometimes it is necessary to check the value of one condition and then check the value of another condition if the first one is met. This is when you would want to use nested if statements. They allow you to check multiple conditions. Just remember to include and "End If" with each condition you test for. If you forget to include this the ASP Runtime will give you an error.

Select Conditional Statements

     Select statements are useful when you want to test one condition and do multiple actions based upon it. The syntax of the select statement is as follows:

Select Case myVarA
    Case "1"
    Case "2"
    Case "3"
    Case "4"
    Case Else
    Response.Write("a equals something else...")
End Select

     What the above code does is check myVarA. If myVarA equals any of the case statements the code under that condition is executed. If none of the case statements match the variable then the code under the Case Else condition is executed.

     Check out Conditionals Part 2 for when to use if and when to use the select case statement.