PowerShell for Microsoft SharePoint 2010 : Variables, Arrays, and Hashtables - Arrays in Windows PowerShell

An array is a container that is used for storing a collection of data elements. An array in Windows PowerShell can contain objects of all types supported by .NET. All arrays are origin zero, meaning that the first element in an array is always at index 0, the second element is at index 1, and so on. Many cmdlets in Windows PowerShell return output in the form of an array.

Here is an example of creating a simple array containing numeric values:

PS > $array = 1,2,3
PS > $array
1
2
3

You can also create an array using the array subexpression operator @, as shown here:

PS > $array = @(1,2,3)

You can access specific elements in arrays. To retrieve the first element, type the following:

PS > $array[0]
1

Notice how we use the value 0 to retrieve the first element, since the indexing of array elements in Windows PowerShell starts with zero. If we used 1, the second element would be returned.

You can change an element in an array by assigning it a new value, as in this example:

PS > $array[1] = "Two"
PS > $array
1
Two
3

Use the += operator to add an element to an array.

PS > $array += "Four"
PS > $array
1
Two
3
Four

You can also count the number of elements in an array by using the Count property.

PS > $array.Count
4

Note

The Count property used in this example is actually an alias for the System.Array Length property. It is available through the types.ps1.xml file, which is a built-in XML file that adds several elements to the .NET Framework types in Windows PowerShell.

When cmdlets return more than one result, Windows PowerShell automatically wraps the result into an array. In the following example, we store the output of the Get-SPWebTemplate cmdlet in a variable and use the Count property to check how many elements the array contains.

PS > $SPWebTemplate = Get-SPWebTemplate
PS > $SPWebTemplate.Count
50

Again, if we want to retrieve the first element, we can simply type the following:

PS > $SPWebTemplate[0]

Name       Title             LocaleId   Custom
----       -----             --------   ------
GLOBAL#0   Global template   1033       False

You can also use ranges when retrieving elements in an array.

PS > $SPWebTemplate[0..2]

Name       Title             LocaleId   Custom
----       -----             --------   ------
GLOBAL#0   Global template   1033        False
STS#0      Team Site         1033        False
STS#1      Blank Site        1033        False

It is even possible to use negative numbers when working with arrays. To retrieve the last element in the array, use -1.

PS > $SPWebTemplate[-1]

Name        Title                      LocaleId   Custom
----        -----                      --------   ------
visprus#0   Visio Process Repository   1033       False