Question

I have (yet another) powershell query. I have an array in powershell which i need to use the remove() and split commands on.

Normally you set an array (or variable) and the above methods exist. On the below $csv2 array both methods are missing, i have checked using the get-member cmd.

How can i go about using remove to get rid of lines with nan. Also how do i split the columns into two different variables. at the moment each element of the array displays one line, for each line i need to convert it into two variables, one for each column.

timestamp Utilization
——— ———–
1276505880 2.0763250000e+00
1276505890 1.7487730000e+00
1276505900 1.6906890000e+00
1276505910 1.7972880000e+00
1276505920 1.8141900000e+00
1276505930 nan
1276505940 nan
1276505950 0.0000000000e+00

$SystemStats = (Get-F5.iControl).SystemStatistics     
$report = "c:\snmp\data" + $gObj + ".csv"

### Allocate a new Query Object and add the inputs needed
$Query = New-Object -TypeName iControl.SystemStatisticsPerformanceStatisticQuery
$Query.object_name = $i
$Query.start_time = $startTime
$Query.end_time = 0
$Query.interval = $interval
$Query.maximum_rows = 0 

### Make method call passing in an array of size one with the specified query
$ReportData = $SystemStats.get_performance_graph_csv_statistics( (,$Query) )

### Allocate a new encoder and turn the byte array into a string
$ASCII = New-Object -TypeName System.Text.ASCIIEncoding
$csvdata = $ASCII.GetString($ReportData[0].statistic_data) 

$csv2 = convertFrom-CSV $csvdata

$csv2

Answer 1

There is no Remove or Split method on .NET’s Array type, or added by the PowerShell wrapper around an Array instance. This is quite easy to show:

PS[64bit] E:\> $a = 1,2,3,4,5
PS[64bit] E:\> $a.GetType()

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     Object[]                                 System.Array


PS[64bit] E:\> Get-Member -InputObject $a


   TypeName: System.Object[]

Name           MemberType    Definition
----           ----------    ----------
Count          AliasProperty Count = Length
Address        Method        System.Object&, mscorlib, Version=2.0.0.0, Culture=neutral, PublicK...
Clone          Method        System.Object Clone()
CopyTo         Method        System.Void CopyTo(array array, int index), System.Void CopyTo(arra...
Equals         Method        bool Equals(System.Object obj)
Get            Method        System.Object Get(int )
GetEnumerator  Method        System.Collections.IEnumerator GetEnumerator()
GetHashCode    Method        int GetHashCode()
GetLength      Method        int GetLength(int dimension)
GetLongLength  Method        long GetLongLength(int dimension)
GetLowerBound  Method        int GetLowerBound(int dimension)
GetType        Method        type GetType()
GetUpperBound  Method        int GetUpperBound(int dimension)
GetValue       Method        System.Object GetValue(Params int[] indices), System.Object GetValu...
Initialize     Method        System.Void Initialize()
Set            Method        System.Void Set(int , System.Object )
SetValue       Method        System.Void SetValue(System.Object value, int index), System.Void S...
ToString       Method        string ToString()
IsFixedSize    Property      System.Boolean IsFixedSize {get;}
IsReadOnly     Property      System.Boolean IsReadOnly {get;}
IsSynchronized Property      System.Boolean IsSynchronized {get;}
Length         Property      System.Int32 Length {get;}
LongLength     Property      System.Int64 LongLength {get;}
Rank           Property      System.Int32 Rank {get;}

Arrays in .NET, and PowerShell, are fixed size. To remove an element you need to copy all but the element to be removed, in PSH this can be done with Where-Object:

$newArray = $oldArray | Where-Object {some-condition-on-$_}

Similarly Select-Object with -First and -Skip parameters can be used to select elements before or after (resp3ectively) an index.

---

NB System.Array does implement System.Collections.ILst but the explicit implementation of IList.Remove just throws a NotImplementedException.