Constant is a named memory location used to hold a value that CANNOT
be changed during the script execution. If a user tries to change a
Constant Value, the Script execution ends up with an error. Constants
are declared the same way the variables are declared.
Declaring Constants
Syntax:
[Public | Private] Const Constant_Name = Value
The Constant can be of type Public or Private. The Use of Public or
Private is Optional. The Public constants are available for all the
scripts and procedures while the Private Constants are available within
the procedure or Class. One can assign any value such as number, String
or Date to the declared Constant.
Example 1:
In this example, the value of pi is 3.4 and it displays the area of the circle in a message box.
<!DOCTYPE html>
<html>
<body>
<script language="vbscript" type="text/vbscript">
Dim intRadius
intRadius = 20
const pi=3.14
Area = pi*intRadius*intRadius
Msgbox Area
</script>
</body>
</html>
Example 2:
The below example illustrates how to assign a String and Date Value to a Constant.
<!DOCTYPE html>
<html>
<body>
<script language="vbscript" type="text/vbscript">
Const myString = "VBScript"
Const myDate = #01/01/2050#
Msgbox myString
Msgbox myDate
</script>
</body>
</html>
Example 3:
In the below example, the user tries to change the Constant Value; hence, it will end up with an
Execution Error.
<!DOCTYPE html>
<html>
<body>
<script language="vbscript" type="text/vbscript">
Dim intRadius
intRadius = 20
const pi=3.14
pi = pi*pi 'pi VALUE CANNOT BE CHANGED.THROWS ERROR'
Area = pi*intRadius*intRadius
Msgbox Area
</script>
</body>
</html>
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