ASP Arrays
Arrays in ASP follow the exact
same form and rules as those
arrays in VBScript. You can create
an array of specific size or you
can create a dynamic sized array.
Below we have examples of both
types of arrays.
ASP Code:
<%
Dim myFixedArray(3) 'Fixed
size array
Dim myDynArray() 'Dynamic size
array
%> |
We are going to focus on fixed
size arrays first and cover
dynamic arrays later on in this
lesson.
Assigning Values to an Array
Let's fill up our fixed size
array with values. Our fixed array
is going to store the names of
famous people. To assign a value
to an array you need to know three
things:
- The name of the array
- The value you want to store
- The position in the array
where you want to store the
value.
An array is a group of
variables that you can access by
specifying the position inside the
array. Our array myFixedArray has
four positions: 0, 1, 2 and 3.
Let's assign some values to our
array.
ASP Code:
<%
Dim myFixedArray(3) 'Fixed
size array
myFixedArray(0) = "Albert
Einstein"
myFixedArray(1) = "Mother
Teresa"
myFixedArray(2) = "Bill Gates"
myFixedArray(3) = "Martin
Luther King Jr."
%> |
ASP Arrays are Zero Based!
If you're a programmer you
might look at that above example
and thing "Hey, you only allocated
three elements for that array, but
you assigned four values! Well,
this can be done because arrays in
ASP are zero based. This means
when you declare fixed array of
size X then you can assign values
for each value from 0 through X.
Below is perfectly functional
ASP code that will go through our
array and print out the contents
of each element. Don't worry if
you are confused by this new for
loop code it will be taught later.
ASP Code:
<%
Dim myFixedArray(3) 'Fixed
size array
myFixedArray(0) = "Albert
Einstein"
myFixedArray(1) = "Mother
Teresa"
myFixedArray(2) = "Bill Gates"
myFixedArray(3) = "Martin
Luther King Jr."
For Each item In myFixedArray
Response.Write(item & "<br
/>")
Next
%> |
Display:
|
Albert Einstein Mother Teresa
Bill Gates Martin Luther King
Jr. |
ASP Dynamic Sized Arrays
To create an array whose size
can be changed at any time simply
do not put a number within the
parenthesis when you declare the
array. When you know what size you
want the array to be use the ReDim
keyword. You may ReDim as many
times as you wish.
If you want to keep your data
that already exists in the array
then use the Preserve keyword.
Below is an example of all these
things we have just talked about.
ASP Code:
<%
Dim myDynArray() 'Dynamic size
array
ReDim myDynArray(1)
myDynArray(0) = "Albert
Einstein"
myDynArray(1) = "Mother
Teresa"
ReDim Preserve myDynArray(3)
myDynArray(2) = "Bill Gates"
myDynArray(3) = "Martin Luther
King Jr."
For Each item In myDynArray
Response.Write(item & "<br
/>")
Next
%> |
Display:
|
Albert Einstein Mother Teresa
Bill Gates Martin Luther King
Jr. |
|