An If Statement is used to make a decision in your ASP
program to execute certain code if some condition is True. Because ASP is
programmed in VBScript by default, when you program an ASP If Statement it is
actually the same as programming a VBScript If Statement.
if statement syntax
ASP's If Statement is slightly different than the If
Statement implementation in most other languages. There are no brackets, or
curly braces, nor are there any parenthesis. Rather the beginning of the code
to be executed in the If Statementwhen its true is marked with Then and the end
of the If Statement is plainly marked with End If. Below is a very basic If
Statement that will always be True.
ASP Code:
<%
Dim myNum
myNum = 6
If myNum = 6 Then
Response.Write("Variable
myNum = 6")
End If
%>
Display:
Variable myNum = 6
You might notice that the "=" operator is used to
both set the value of myNum to 6 at first, then it is used to compare myNum to
6 in our If Statement. This dual use of the equals operator is confusing to
many, but it might help you to remember that in ASP you cannot set the value of
variables within If Statements, which means that the "=" can only
compare!
asp - if else conditional statement
Sometimes you might want to execute some code both when the
If Statement is True and some different code when it is False. Just like other
programming languages, you can do this in ASP with the use of the Else keyword.
Below is an example that will always be false, so that the Else portion of the
If Statement is always executed.
ASP Code:
<%
Dim myNum
myNum = 23
If myNum = 6 Then
Response.Write("Variable
myNum = 6")
Else
Response.Write("**Variable
myNum = " & myNum)
End If
%>
Display:
**Variable myNum = 23
asp - elseif conditional statement
With a normal If Statement you can only check one condition,
but at times you will want to check for multiple conditions. In ASP you can do
this with ElseIf, which is the name given to an If Statement that depends on
another If Statement.
Think about it in plain english: If something is true Then
do this ElseIf second something is true Then do this, etc. You may have used
the ElseIf condition statement in other programming languages, but if not just
know that you cannot have an ElseIf statement without first having an if
statement.
Below is an example whose second if statement (elseif) is
always true.
ASP Code:
<%
Dim myFastfood
myFastfood = "JBox"
If myFastfood = "McD's" Then
Response.Write("Happy
Meal Por Favor!")
ElseIf myFastfood = "JBox" Then
Response.Write("Two
tacos please!")
Else
Response.Write("Foot-long
turkey sub.")
End If
%>
Display:
Two tacos please!
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