Variables are used to store information. VB Script Variables are declared like
visual basic except, variable type is not specified because VB Script variables are
type variant that can store different types of values. For example, The following
example are string variable declaration for VB & VBScript;
script variable: dim name, visual basic variable:
dim name as string. Variable must not exceed 255
characters, cannot contain an embedded period, unique in the scope in which it's
declared, and must start with letter. Variable can be declared with
dim, public or private. VBScript allows you to use undeclared variable with out
the use of Option Explicit. This kind of use is discouraged because of the
risk involved to misuse or misspell a variable. Option Explicit prevents the use of
undeclared variable and if used it must
appear in the head of the script before any procedures.
The following are sample variable to see
how to store
information into a variable.
dim name
dim CustNno
dim MonthlyFee
name="B. Danyeer"
CustNo="11122"
MonthlyFee=100 We declared three variables; name, CustNo, MonthlyFee
and initialized each of them with value. The variable name has the value B.
Danyeer. Anything with quotation " " is string and cannot be
calculated as a number. MonthlyFee is the only number variable that can be
calculated or has number value. If undeclared variable is used, then the
[option explicit] will give you an error message.
You declare more than one variables in one statement by separating each variable name
with a comma.
For example:
Dim firstName, middleName, lastName, Right
You cannot assign value to more than one variable in one statement unless it's an array.
VB Script Arrays
Sometimes you want to assign more than one value to a single variable. This is called
an array variable. Here is how an array is declared: dim cars(3)
. This simply declares a variable called cars that contain 4 values. Array
index or elements start with zero, so it's zero to three that makes up four car-
values. An array can be a dynamic array that takes any number of elements by not
providing the elements like this: dim cars(), but we deal with fixed-size arrays in
this tutorial.
To assign a value into array element, use the name and the index number. Here is an
example that assigns values into the array declared above.
cars(0)="Jeep Grand Cherokee" cars(1)="Jeep Wrangler" cars(2)="Jeep Liberty"
cars(3)="Jeep Cherokee Briarwood" Now we know that every element of the array
has value. We can retrieve the data one at a time or all at once. For example, I can
retrieve Jeep Grand Cherokee by using cars(0) or by re-assigning to it an another
variable like this, car1=cars(0). We can also access to the array data using loop
like this: for x=0 to 3 msgbox(cars(x))
next This simply display all the cars on message box one at a time.
Here is a complete example using arrays and variables.
<html>
<body>
<script type="text/vbscript">
dim name
dim age
name=inputbox("Please enter your name:")
age=inputbox("Enter your age:")
winNum=age*2-2+5*3-3+9/2
dim cars(3)
cars(0)="S2000"
cars(1)="Odyssey"
cars(2)="Passport"
cars(3)="Accord"
document.write("Hello " & name)
document.write("Your lucky number to win one of the following Honda cars is: " &
winNum &"<br>")
document.write("Cars to be won!!!"& "<br>")
for i=0 to 3
document.write(cars(i) & "<br>")
next
</script>
</body>
</html>
We saw most of
this staff previously. The first thing this example does is; declares name and age
variables. Then pops up input box asking the user a name, then another one asking
age. It adds and multiples some numbers by the age. Then declares and populates an
array. Document.write() method, writes the provided argument
on the screen. & ties strings. You must use & when writing
more then one variable or strings in one statement. Finally, it retrieves the array
and writes on the screen using loops. Note that we can use html tag with vbscript statement for example document.write("hellow"
& "<br>") writes hellow and breaks the line with html tag enclosed with.
.