Whatis an Array:
We know very well that a variable is a container to
store a value. Sometimes, developers are in a position to hold more than one
value in a single variable at a time. When a series of values are stored in a
single variable, then it is known as array variable.
Arrays are declared the same way a variable has been
declared except that the declaration of an array variable uses parenthesis. In
the below example, the size of the array is mentioned in the brackets.
'Method 1 : Using Dim
Dim arr1() 'Without
Size
'Method 2 : Mentioning the Size
Dim arr2(5)
'Declared with size of 5
'Method 3 : using 'Array' Parameter
Dim arr3
arr3 = Array("america","india","itlay")
Although, the Array size is indicated as 5, it can
hold 6 values as array index starts from ZERO.
VBScript Arrays can store any type of variable in an
array. Hence, an array can store an integer, string or characters in a single
array variable.
The values are assigned to the array by specifying
array index value against each one of the values to be assigned. It can be a
string.
Example :
<!DOCTYPE html>
<html>
<body>
<script language="vbscript"
type="text/vbscript">
Dim arr(5)
arr(0) = "1" 'Number as String
arr(1) = "VBScript" 'String
arr(2) = 100 'Number
arr(3) = 2.45 'Decimal Number
arr(4) = #10/07/2013# 'Date
arr(5) = #12.45 PM# 'Time
document.write("Value stored in Array index 0 :
" & arr(0) & "<br />")
document.write("Value stored in Array index 1 :
" & arr(1) & "<br />")
document.write("Value stored in Array index 2 :
" & arr(2) & "<br />")
document.write("Value stored in Array index 3 :
" & arr(3) & "<br />")
document.write("Value stored in Array index 4 :
" & arr(4) & "<br />")
document.write("Value stored in Array index 5 :
" & arr(5) & "<br />")
</script>
</body>
</html>
When the above code is saved as .HTML and executed
in Internet Explorer, it produces the following result:
Value stored in Array index 0 : 1
Value stored in Array index 1 : VBScript
Value stored in Array index 2 : 100
Value stored in Array index 3 : 2.45
Value stored in Array index 4 : 7/10/2013
Value stored in Array index 5 : 12:45:00 PM
Multi Dimension Arrays
Arrays are not just limited to single dimenstion and
can have a maxinum of 60 dimensions. Two-dimension arrays are the most commonly
used ones.
Example :
In the below example, a multi-dimension array is
declared with 3 rows and 4 columns.
<!DOCTYPE html>
<html>
<body>
<script language="vbscript"
type="text/vbscript">
Dim arr(2,3) '
Which has 3 rows and 4 columns
arr(0,0) = "America"
arr(0,1) = "England"
arr(0,2) = "New Zealand"
arr(0,3) = "India"
arr(1,0) = "Korea"
arr(1,1) = "west indies"
arr(1,2) = "Bangladesh"
arr(1,3) = "srilanka"
arr(2,0) = "Malaysia"
arr(2,1) = "Australia"
arr(2,2) = "Brittan"
arr(2,3) = "Italy"
document.write("Value in Array index 0,1 :
" & arr(0,1) & "<br
/>")
document.write("Value in Array index 2,2 :
" & arr(2,2) & "<br
/>")
</script>
</body>
</html>
When the above code is saved as .HTML and executed
in Internet Explorer.
ReDim Statement is used to Declare dynamic-array
variables and allocate or reallocate storage space.
Preserve- An Optional parameter used to preserve the data in an existing array when you
change the size of the last dimension.
varname-
A Required parameter, which denotes Name of the variable, which should follow
the standard variable naming conventions.
subscripts-
A Required parameter, which indicates the size of the array.
Example
:
In the below example, an array has been redefined
and then preserved the values when the existing size of the array is changed.
Note
:
Upon resizing an array smaller than it was originally, the data in the
eliminated elements will be lost.
<!DOCTYPE html>
<html>
<body>
<script language="vbscript"
type="text/vbscript">
Dim a()
i=0
redim a(5)
a(0)="XYZ"
a(1)=41.25
a(2)=22
REDIM
PRESERVE a(7)
For i=3 to 7
a(i)= i
Next
'to Fetch
the output
For i=0 to
ubound(a)
Msgbox
a(i)
Next
</script>
</body>
</html>
When we save the above script as HTML and execute it
in Internet Explorer, it produces the following result.
XYZ
41.25
22
3
4
5
6
7
There are various inbuilt functions within VBScript
which help the developers to handle arrays effectively. All the methods that
are used in conjuction with arrays are listed below. Please click on the method
name to know in detail.
Function Description
LBound A
Function, which returns an integer that corresponds to the smallest subscript
of the given arrays.
UBound A Function, which returns an integer
that corresponds to the Largest subscript of the given arrays.
Split A Function, which returns an
array that contains a specified number of values. Splitted based on a
Delimiter.
Join A Function, which returns a
String that contains a specified number of substrings in an array. This is an
exact opposite function of Split Method.
Filter
A Function, which returns a zero based array that contains a subset of a
string array based on specific filter criteria.
Is
Array A Function, which returns a
boolean value that indicates whether or not the input variable is an array.
Erase
A Function, which recovers the allocated memory for
the array variables.
No comments:
Post a Comment