Read variables from XML

Question

Is it somehow possible to read variables and values from xml into an PowerShell script without specifying each of them separately?
For example I've set the following variables:
$arrPostcode @()
$arrPostcode += ,@('1234AB', 'City1')
$arrPostcode += ,@('4567CD', 'City2')
$blnHome =$True
$blnNld =$False
$intNumbers =556
$strText ='Something'
And I have a xml file like (can be ajusted when required to get a better result):<?xml version="1.0"?>
<Objects>
<Object Type="System.Management.Automation.PSVariable">
<Property Name="Name" Type="System.String">arrPostcode</Property>
<Property Name="Value" Type="System.Object[]">
<Property Type="System.Object[]">
<Property Type="System.String">9874ZX</Property>
<Property Type="System.String">City5</Property>
</Property>
<Property Type="System.Object[]">
<Property Type="System.String">6541UH</Property>
<Property Type="System.String">City3</Property>
</Property>
</Property>
<Property Name="ModuleName" Type="System.String" />
</Object>
<Object Type="System.Management.Automation.PSVariable">
<Property Name="Name" Type="System.String">blnHome</Property>
<Property Name="Value" Type="System.Boolean">False</Property>
</Object>
<Object Type="System.Management.Automation.PSVariable">
<Property Name="Name" Type="System.String">blnNld</Property>
<Property Name="Value" Type="System.Boolean">True</Property>
</Object>
<Object Type="System.Management.Automation.PSVariable">
<Property Name="Name" Type="System.String">intNumbers</Property>
<Property Name="Value" Type="System.Int32">13</Property>
</Object>
<Object Type="System.Management.Automation.PSVariable">
<Property Name="Name" Type="System.String">strText</Property>
<Property Name="Value" Type="System.String">World</Property>
</Object>
</Objects>And say I want to use the 'default' values if the xml file was not
found, but if the xml file is found I want to use (replace) the
variables and values defined in that xml file.

Answer 1

First of all your sample code I not PowerShell.  Second XML has no "variables".  It is a structured document.  When imported into PowerShell it shows up as an XMLDocument object.  If you want values from the document you have
to extract them by direct reference or query.
The simple answer to your question is "yes".  You can assign a default to a variable which will be updated only if the value exist in the document.  The rest cannot be determined from what you have asked.
Start by learning some of the basics of PowerShell scripting and ask a new question when you can see what it is you want to do.
Here is a good starting point:
http://technet.microsoft.com/en-us/scriptcenter/dd793612.aspx
The XML you have posted is actually PowerShell object serialization format so it is already a PS object.  It is not just arbitrary XML.  It isnot clear howyou acquired this which is another reason to learn more of the PS basics. 
It appears that you have used ConvertTo-XML to create an XML object.  This can be sued to dave values and state but may not bethe best method.  Export-CliXml can persist an object and restore it more directly.  We can wrap this in a function
that can be used to default values.
Look into Export.CliXml and Import-CliXml.
Example:
$ziptable=@()
$myProps=@{
Name='Detroit'
ZipCode='20192'
$ziptable+=New-Object PsObject -Property $myProps
$myProps=@{
Name='New York'
ZipCode='90100'
$ziptable+=New-Object PsObject -Property $myProps
$ziptable | Export-CliXml myzips.clixml
$savezips = Import-CliXml myzips.clixml
Result demo:
PS C:\scripts> $savezips
ZipCode Name
20192 Detroit
90100 New York
PS C:\scripts> $savezips[0]
ZipCode Name
20192 Detroit
PS C:\scripts> $savezips[0].Zipcode
20192
PS C:\scripts>
Of course a simple lookup table would be done with a pure hash and persisted.  For more comples things I would use a custom dataset which can also be persited and restored the same way.  Sort of a poor man's portable database.
¯\_(ツ)_/¯