Update-List

Add and remove items from a property value that contains a collection of objects.

Syntax
      Update-List [-Add Object[]] [-Remove Object[]]
         [[-Property] string] [-InputObject psobject] [CommonParameters]

      Update-List -Replace Object[]
         [[-Property] string] [-InputObject psobject] [CommonParameters]

Key
   -Add Object[]
       The property values to be added to the collection.
       Enter the values in the order that they should appear in the collection.

   -InputObject psobject
       The objects to be updated.
       The object to be updated may be piped to Update-List.

   -Property string
       The property that contains the collection that is being updated.
       If omitted, Update-List will return an object that represents
       the change instead of changing the object.

   -Remove Object[]
       The property values to be removed from the collection.

   -Replace Object[]
       Specifies a new collection.
       This parameter replaces all items in the original collection
       with the items specified by this parameter.

   CommonParameters:
       -Verbose, -Debug, -ErrorAction, -ErrorVariable, -WarningAction, -WarningVariable,
       -OutBuffer -OutVariable.

Update-List adds items to and removes items from a property value of an object, and then it returns the updated object. This cmdlet is designed for properties that contain collections of objects.

The -Add and -Remove parameters add individual items to and remove them from the collection. The -Replace parameter replaces the entire collection.

If no property is specified in the command, Update-List will return an object that describes the update instead of updating the object. The update object may be submitted to cmdlets that change objects, such as Set-* cmdlets.

This cmdlet works only when the property that is being updated supports the IList interface that Update-List uses. Also, any Set-* cmdlets that accept an update must support the IList interface. The core cmdlets that are installed with PowerShell do not support this interface.

Examples

Add A and B and remove X and Y from the Aliases property of an Exchange mailbox:

PS C:\> get-mailbox | update-list -Property aliases -Add "A","B" -Remove "X","Y" | set-mailbox Hello

Add A and B to the value of the Aliases property of a Exchange mailbox and remove X and Y. This command has the same effect as the previous command, although it has a slightly different format:

PS C:\> $mb = get-mailbox
PS C:\> update-list -InputObject $mb -Property aliases -Add "A","B" -Remove "X", "Y" | set-mailbox

Add A and B and remove X and Y from the Aliases property of an Exchange mailbox, again this command has the same effect:

PS C:\> get-mailbox | set-mailbox -alias (update-list -Add "A", "B" -Remove "X","Y")

“You never have to change anything you got up in the middle of the night to write” ~ Saul Bellow

Related PowerShell Cmdlets:

Set-Content - Set content in an item (specific location).
Set-Item - Change the value of an item.