PowerShell in Sharepoint 2010 – Basics Part 1
Introduction
In PowerShell basic series part 1, we can learn how to work with variables, arrays and hashtables. The basic series is very important to understand the complex codes of powershell. This series will be worth reference guide as most of powershell developers are not aware of the syntax and usage.
Usage Variables
Following is the simplest way of creating variables and assign value
$firstName = "Adi" $empId = 999
Other commands to create, retrieve and set variables
New-Variable cmdlet is used to create variables with additional features like description and options like setting as readonly variable
Following code creates new readonly variable ‘SiteName’ and assigns value to it. It also provides description what the variable is
New-Variable -Name SiteName -Value "PowershellTraining" -Description "Stores name of the site" -Option ReadOnly
Get-Variable cmdlet is used get the value of variable
Get-Variable -Name SiteName
Few other variable related cmdlets are Set-Variable, Clear-Variable, Remove-Variable
In general, simplest way is used rather than cmdlets to create and assign values to the variables
Data Types
When we use assign operator “=”, automatically the suitable datatype will be assigned to the variable.
In the following example we have set values and the variables will become automatically to string and integer variables
$firstName = "Adi" $empId = 999
Use GetType() method with FullName property to get the datatype of the variable
$firstName.GetType().FullName $empId.GetType().FullName
output will be
System.String
System.Int32
We can also create specific data type variable like the following code
[int32]$empId = 32
This will create integer variable directly, rather than powershell to decide the conversion.
If we try to assign string value for the above variable, it will give runtime error.
Other common data types used in powershell are
DataType |
Usage |
| [string] | [string]$companyName = “AdiCodes” |
| [int] | [int32]$empId = 999 |
| [int64] | [int64]$totalVisits = 9900000 |
| [char] | [char]$Leaves = 20 |
| [string] | [bool]$IsVisible = $true |
| [byte] | [byte]$byVal = 555 |
| [decimal] | [decimal]$myDecimal = 11.22 |
| [float] | [float]$myFloat = 11.22 |
Automatic variables or Fixed variables
Powershell has predifined fixed variables which can be handy while development.Some of the common fixed variables are
Fixed variable |
Description |
| $$ | The last token in the last line received by the session |
| $? | True or false, depending on the last performed operation |
| $^ | The first token from the last line received by the session |
| $_ | The current object in the pipeline object |
| $args | An array of values passed to a function or a script |
| $Error | An array of error objects representing the most recent error that occurred |
| $false | Boolean false |
| $true | Boolean true |
| $foreach | The enumerator of a foreach loop |
| $Home | User’s home directory |
| $NULL | An empty value |
| $PID | The process identifier of the process that is hosting the current Windows PowerShell session |
| $Profile | The full path to the Windows PowerShell profile for the current user |
| $PsHome | The full path of the installation directory of Windows PowerShell |
| $PsScriptRoot | The directory from which the script module is being executed |
| $PsUICulture | The name of the user interface culture that is currently in use in the operating system |
| $Pwd | The current directory |
Arrays
An array in PowerShell can contain objects of all types supported by .NET.
Creating an array
$EmIds = 11,22,33
or
$EmIds = @(11,22,33)
Access or assign array element
var $firstId = $EmIds[0] $EmIds[1] = 222
Add an array element
$EmIds += "444"
Get array Count
$totalEmps = $EmIds.Count
Count is nothing but an alias in System.Array Length property
Hash Tables
HashTables use key value pairs to access values
Creating hashtable
$empInfo = @{"FirstName"="Adi";"Company"="AdiCodes"}
Access elements
$empInfo["FirstName"]
Conclusion
I hope you got some basic information on variable, arrays and hashtables. We will see in further series what are the various operators and looping in powershell
Powershell in SharePoint 2010
SharePoint Server 2010 Getting started with windows PowerShell Part 1
PowerShell Basics SharePoint
PowerShell using Arrays
PowerShell using Hash Tables
PowerShell DataTypes in SharePoint
April 12, 2012
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Tags: arrays in powershell, hashtable in powershell, Powershell, PowerShell 2.0, SharePoint 2010, Variables in Powershell В· Posted in: Packaging and Deployment, Powershell, Sharepoint 2010
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