Operatoren
**********
 

Variablen werden häufig mit Hilfe von Operatoren weiterverarbeitet. Die gängigsten Operatoren sind die mathematischen Operatoren wie Addition, Multiplikation, Division,etc. Im Anhang finden Sie eine Übersicht :ref:`mathematischeoperatoren`.

.. index:: Operator


.. _powershell_variablen:

Powershell-Variablen
--------------------

==================== =========================================================
Variable  	     Bedeutung
==================== =========================================================
$^ 			Contains the first token of the last line input into the shell
$$ 			Contains the last token of the last line input into the shell
$_ 			The current pipeline object; used in script blocks, filters, Where-Object, ForEach-Object, and Switch
$? 			Contains the success/fail status of the last statement
$Args 			Used in creating functions requiring parameters
$Error 			If an error occurred, the error object is saved in the $error variable.
$ExecutionContext 	The execution objects available to cmdlets
$foreach 		Refers to the enumerator in a foreach loop
$HOME 			The user's home directory; set to %HOMEDRIVE%\%HOMEPATH%
$Input 			Input is piped to a function or code block.
$Match 			A hash table consisting of items found by the -match operator
$MyInvocation 		Information about the currently executing script or command-line
$PSHome 		The directory where PS is installed
$Host 			Information about the currently executing host
$LastExitCode 		The exit code of the last native application to run
$true 			Boolean TRUE
$false 			Boolean FALSE
$null 			A null object
$this 			In the Types.ps1xml file and some script block instances, this represents the current object
$OFS 			Output Field Separator used when converting an array to a string
$ShellID 		The identifier for the shell. This value is used by the shell to determine the ExecutionPolicy and what profiles are run at Startup
$StackTrace 		Contains detailed stack trace information about the last error
==================== =========================================================




.. _vergleichsoperator:

Vergleichsoperatoren
--------------------

=================== =========== ================== ===================== ================
 Operator           klassisch   Beschreibung        Beispiel              Ergebnis     
=================== =========== ================== ===================== ================
-eq,-ceq, -ieq 	     = 	        Gleichheit 	    10 -eq 15 	          $true
-ne, -cne, -ice      <> 	Ungleichheit 	    10 -ne 15 	          $true
-gt,-cgt, -igt 	     > 	        Größer 	            10 -gt 15 	          $false
-ge,-cge, -ige 	     >= 	Größer gleich       10 -ge 15 	          $false
-lt,-clt, -ilt 	     < 	        Kleiner 	    10 -lt 15 	          $true
-le,-cle, -ile 	     <= 	Kleiner gleich      10 -le 15 	          $true
-contains [#]_         		Enthält             1,2,3 -contains 1     $true
-notcontains                    Nicht enthält       1,2,3 -notcontains 1  $false
-is 		                Typgleichheit 	    $feld -is [array]      $true
-like		     		Wildcard
-notlike			Wildcard
-match				regulärer Ausdruck
-notmatch			regulärer Ausdruck
=================== =========== ================== ===================== ================


.. _logischeOperatoren:

Logische Operatoren
-------------------

.. image:: images/logical_operators.jpg


.. _mathematischeoperatoren:

Mathematische Operatoren
------------------------

Es gelten folgende Voraussetzungen

.. code-block:: sh  

    PS> $a = 10
        $b = 15


=================== ===========  ===================== ================
 Operator           klassisch     Beispiel              Ergebnis     
=================== ===========  ===================== ================
Addition 	       \+ 	    $a + $b 	          25
Division               \- 	    $a - $b 	          -5
Multiplikation         \* 	    $a * $b 	          $false
Modulo [#]_ 	       % 	    $a % 3 	           1
Increment	       \+\+	    $a++                  11
Decrement 	       \- \-        $b\- \-		  14
=================== ===========  ===================== ================

.. image:: images/arithmetic_operator.png