In ASP there are four conditional statements:

• If...Then statement - executes a set of code when a condition is true
• If...Then...Else statement - select one of two sets of lines to execute
• If...Then...ElseIf statement - select one of many sets of lines to execute
• Select Case statement - select one of many sets of lines to execute

If...Then

Use the If...Then statement to execute some code if a condition is true.
You just tell the code to perform one action if a condition is true (in this case If i=10).

                    
Dim i: i=10

If i = 10 Then response.write("Hello")

OUTPUT:
Hello
                    
                

If you want to execute more than one statement when a condition is true, you must put each statement on separate lines, and end the statement with the keyword End If:

You just tell the code to perform multiple actions if the condition is true like the example below.
Here the two actions are write Hello and incrementing i by 1

                    
If i=10 Then
  response.write("Hello")
   i = i+1
End If
                    
                

If you want to execute a statement if a condition is true and execute another statement if the condition is not true, you must add the Else keyword:

In the example below, the first block of code will be executed if the condition is true, and the other block will be executed otherwise (if i is greater than or equal to 10).

                    
i=hour(time)

If i < 10 Then
  response.write("Good morning!")
Else
  response.write("Have a nice day!")
End If

OUTPUT if less than 10;
Good morning!

OUTPUT if 10 or greater:
Have a nice day!
                    
                

If...Then...ElseIf

You can use the If...Then...ElseIf statement if you want to select one of many blocks of code to execute:

                    
i=hour(time)

If i = 10 Then
  response.write("Just started...!")
ElseIf i = 11 Then
  response.write("Hungry!")
ElseIf i = 12 Then
  response.write("Ah, lunch-time!")
ElseIf i = 16 Then
  response.write("Time to go home!")
Else
  response.write("Unknown")
End If

OUTPUT if i = 10:
Just started...!

OUTPUT if i = 11:
Hungry!

OUTPUT if i = 12:
Ah, lunch-time!

OUTPUT if i = 16:
Time to go home!

OUTPUT if none of the above:
Unknown
                    
                

Select Case

You can also use the Select Case statement if you want to select one of many blocks of code to execute:

This is how it works: First we have a single expression (most often a variable), that is evaluated once. The value of the expression is then compared with the values for each Case in the structure. If there is a match, the block of code associated with that Case is executed.

                    
d=weekday(date)

Select Case d
  Case 1
    response.write("Sleepy Sunday")
  Case 2
    response.write("Monday again!")
  Case 3
    response.write("Just Tuesday!")
  Case 4
    response.write("Wednesday!")
  Case 5
    response.write("Thursday...")
  Case 6
    response.write("Finally Friday!")
  Case else
    response.write("Super Saturday!!!!")
End Select

OUTPUT case 1:
Sleepy Sunday

OUTPUT case 2:
Monday again!

OUTPUT case 3:
Just Tuesday!

OUTPUT case 4:
Wednesday!

OUTPUT case 5:
Thursday...

OUTPUT case 6:
Finally Friday!

OUTPUT case 7:
Super Saturday!!!
                    
                

Loops and Conditionals are the heart of PHP and any code and is what makes it all tick! Happy Coding!