Applies to: Exchange Server 2010 SP2, Exchange Server 2010 SP3

Topic Last Modified: 2009-02-16

An array provides a data structure that can be used to store a collection of data elements of the same type. The Exchange Management Shell supports all kinds of data elements. See the following sections for information about:

Creating Arrays

Reading Arrays

Manipulating Arrays

Associative Arrays

For detailed information about how to use arrays, run the following command in the Shell:

Get-Help About_Array

You can create and initialize arrays by assigning multiple values to a variable. The values that are stored in the array are delimited by using a comma and are separated from the variable name by the = assignment operator. For example, suppose you want to create an array that is named $Example that contains the following seven integer values: 22, 5, 10, 8, 12, 9, 80. To create the array, enter the following command:

$Example = 22,5,10,8,12,9,80

In the array, the first data element is at index position 0, the second is at position 1, and so on.

You can reference an array by its variable name, such as $Example. You can reference a specific value within the array by using the index number of the position in the array where the value is stored. For example, to reference the first data element in the $Example array, enter the following command:

Write-Host $Example[0]

The Shell will return the value 22 because that is stored in the first array element.

To change the value of a single item in an array, specify the array name, the index you want to modify, the = assignment operator, and the new value that you want to use instead of the existing value. For example, to change the value of the second item in the $Example array, index position 1, to 10, enter the following command:

$Example[1] = 10

You can also use the SetValue method to change a value. The following example changes the second value, index position 1, of an array named $Example to 500:


You can append a value to the end of an existing array. For example, to add an additional integer, such as 200, to the $Example array, enter the following command:

$Example += 200

Associative arrays are the same as regular arrays. However, they enable the assignment of key-value pairs to a variable. For example, you may want to assign values to keys in an array to be called on when a command is being processed. The following example creates an associative array:

$Example = @{blue = 1; red = 2,3}

When you enter $Example on the command line, you see the following output:

Key                            Value
---                            -----
red                            {2, 3}
blue                           1

You can retrieve the information that is stored in the array by calling the array as follows:


The previous example returns a value 1.

Because multiple values were assigned to the red key, those values make up a nested array. You can reference the values in this nested array by using their index value. You can retrieve the information that is stored in the key's nested array by calling the associative array, $Example, with the red key and the index of the nested array location that you want to retrieve 1, as follows:


The previous example returns the value 3.

For more information about associative arrays, run the following command in the Shell:

Get-Help About_Associative_Array