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    Describes how to use methods to perform actions on objects in Windows  


    Windows PowerShell uses objects to represent the items in data stores or 
    the state of the computer. For example, FileInfo objects represent the 
    files in file system drives and ProcessInfo objects represent the  
    processes on the computer. 
    Objects have properties, which store data about the object, and methods 
    that let you change the object. 
    A "method" is a set of instructions that specify an action you can perform 
    on the object. For example, the FileInfo object includes the CopyTo method 
    that copies the file that the FileInfo object represents. 
    To get the methods of any object, use the Get-Member cmdlet. Use its  
    MemberType property with a value of "Method". The following command 
    gets the methods of process objects. 
        PS C:\>Get-Process | Get-Member -MemberType Method 
           TypeName: System.Diagnostics.Process 
         Name                      MemberType Definition 
         ----                      ---------- ---------- 
         BeginErrorReadLine        Method     System.Void BeginErrorReadLine() 
         BeginOutputReadLine       Method     System.Void BeginOutputReadLine() 
         Kill                      Method     System.Void Kill() 
         Refresh                   Method     System.Void Refresh() 
         Start                     Method     bool Start() 
         ToString                  Method     string ToString() 
         WaitForExit               Method     bool WaitForExit(int milliseconds), System.Void WaitForExit() 
         WaitForInputIdle          Method     bool WaitForInputIdle(int milliseconds), bool WaitForInputIdle() 
    To perform or "invoke" a method of an object, type a dot (.), the method 
    name, and a set of parentheses "()". If the method has arguments, place the  
    argument values inside the parentheses. The parentheses are required  
    for every method call, even when there are no arguments. 
    For example, the following command invokes the Kill method of processes 
    to end the Notepad process on the computer. As a result, the instance 
    of Notepad closes. (The Get-Process command is enclosed in parentheses  
    to insure that it runs before the Kill method is invoked. 
        (Get-Process Notepad).Kill() 
    Another very useful process is the Split method of strings. The  
    split method takes a delimiter character argument that tells the 
    method where to split the string. 
        PS C:\>$a = "Try-Catch-Finally" 
        PS C:\>$a.Split("-") 
    As shown in the previous examples, you can invoke a method on an 
    object that you get by using a command or an object in a variable. 
    Starting in Windows PowerShell 4.0, method invocation by using 
    dynamic method names is supported. 


    To find definitions of the methods of an object, go to help topic for 
    for the object type in MSDN and look for its methods page. For example, 
    the following page describes the methods of process objects  
    To determine the arguments of a method, review the method definition, 
    which is like the syntax diagram of a Windows PowerShell cmdlet. 
    A method definition might have one or more method signatures, which are 
    like the parameter sets of Windows PowerShell cmdlets. The signatures  
    show all of the valid formats of commands to invoke the method.    
    For example, the CopyTo method of the  
    FileInfo class contains the following two method signatures: 
        1. CopyTo(String destFileName) 
        2. CopyTo(String destFileName, Boolean overwrite) 
    The first method signature takes the destination file name (and 
    a path). The following example use The first CopyTo method to copy  
    the Final.txt file to the C:\Bin directory. 
        (Get-ChildItem c:\final.txt).CopyTo("c:\bin\final.txt") 
    The second method signature take a destination file name and a  
    Boolean value that determines whether the destination file should 
    be overwritten, if it already exists.  
    The following example use The second CopyTo method to copy  
    the Final.txt file to the C:\Bin directory, and to overwrite 
    existing files. 
        (Get-ChildItem c:\final.txt).CopyTo("c:\bin\final.txt", $true) 


    The methods of one ("scalar") object of a particular type 
    are often different from the methods of a collection of objects  
    of the same type. 
    For example, every process has a Kill method, but a collection  
    of processes does not have a Kill method.  
    Beginning in Windows PowerShell 3.0, Windows PowerShell tries 
    to prevent scripting errors that result from the differing 
    methods of scalar objects and collections. 
    Beginning in Windows PowerShell 4.0, collection filtering by using 
    a method syntax is supported. 
    If you submit a collection, but request a method that exists  
    only on single ("scalar") objects, Windows invokes the method 
    on every object in the collection. 
    If the method exists on the individual objects and on the  
    collection, Windows PowerShell does not alter the result. 
    This feature also works on properties of scalar objects and  
    collections. For more information, see about_Properties. 


    The following example runs the Kill method of individual 
    process objects on a collection of process objects. This      
    example works only on Windows PowerShell 3.0 and later 
    versions of Windows PowerShell. 
    The first command starts three instances of the Notepad  
    process. The second command uses the Get-Process command 
    to get all three instance of the Notepad process and save 
    them in the $p variable.  
        PS C:\>Notepad; Notepad; Notepad 
        PS C:\>$p = Get-Process Notepad 
    The third command uses the Count property of all 
    collections to verify that there are three processes 
    in the $p variable. 
        PS C:\>$p.Count 
    The fourth command runs the Kill method on all  
    three processes in the $p variable.  
    This command works even though a collection  
    of processes does not have a Kill method. 
        PS C:\>$p.Kill() 
    The fifth command uses the Get-Process command 
    to confirm that the Kill command worked. 
        PS C:\>Get-Process Notepad 
        Get-Process : Cannot find a process with the name "notepad". Verify the process name and call the cmdlet again. 
        At line:1 char:12 
        + get-process <<<<  notepad 
            + CategoryInfo          : ObjectNotFound: (notepad:String) [Get-Process], ProcessCommandException 
            + FullyQualifiedErrorId : NoProcessFoundForGivenName,Microsoft.PowerShell.Commands.GetProcessCommand 
     To perform the same task on Windows PowerShell 2.0, 
     use the Foreach-Object cmdlet to run the method 
     on each object in the collection. 
        PS C:\>$p | Foreach-Object {$_.Kill()}