Not able to parse multiline array in powershell - powershell

Question

My aws cli returns multiline array with nested hash, I am not able to parse output to get appropriate values from it
>Write-Host $a
[
[
[
{
"VolumeID": "vol-fxxxxxx"
}
]
]
]
If I do $a[0], it returns first line i.e. "[" same with incremental indexs.
How I can parse this array and get the volumeID from it ?
Thanks
Additional details :
Thanks for your valuable answers. Here is the class name of the above object :
> $a.getType()
IsPublic IsSerial Name BaseType
-------- -------- ---- --------
True True Object[] System.Array
> $a | Where-Object ($_ -like "*Volume*")
> $a | ConvertFrom-Json
ConvertFrom-Json : Invalid JSON primitive:
Microsoft.PowerShell.Commands.Internal.Format.FormatEntryData.
At line:1 char:6
+ $a | ConvertFrom-Json
+ ~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [ConvertFrom-Json], ArgumentException
+ FullyQualifiedErrorId : System.ArgumentException,Microsoft.PowerShell.Commands.ConvertFromJsonCommand
Hi Martin Brandl, TessellatingHeckler I have updated with your question, could you please help me out on the same.
Thanks

Answer 1

same with incremental indexs
I can't make sense of incremental indexes doing the same, and returning the first line, but it looks like it's either:
A multiline string ($a.gettype() has Name: String):
$b = $a | ConvertFrom-Json
$b[0][0][0].VolumeID
or, an array of string ($a.gettype() Name is Object[] or String[]), do this first, then convert from JSON:
$a = -join $a

Answer 2

You could use the where-object cmdlet.
$a | where-object {$_ -like "*Volume*"}
More information on the where-object cmdlet can be found here: https://technet.microsoft.com/en-us/library/ee177028.aspx
Thanks, Tim.