Powershell String Splitting discrepency

Question

I am trying to split a string in PowerShell by calling $varname.split(','). This works fine when I am in a PowerShell console, but not when I invoke the script directly.

From the Command Prompt: powershell .\scriptname.ps1

Method invocation failed because [System.Object[]] doesn't contain a method named 'split'.
At C:\scriptname.ps1:92 char:30
+         reboot $varname.split <<<< (',')
    + CategoryInfo          : InvalidOperation: (split:String) [], RuntimeException
    + FullyQualifiedErrorId : MethodNotFound

Again, this works perfectly fine when I run it in the ISE or directly from a PS prompt. Thoughts?

Edit: I've provided my script below. I'm sort of new to powershell, so I don't see anything that would cause a variable to behave as an array only when called through the commandline.

[string]$servers
[string]$filepath
[string]$account  = $([System.Security.Principal.WindowsIdentity]::GetCurrent().Name)
[string]$mode
[bool]  $reboot   = $FALSE

Write-Host "========================================"
Write-Host "| Windows Server Shutdown Utility v1.0 |"
Write-Host "========================================"

Function usage(){
    Write-Host "Arguments are accepted in any order as long as the data follows the mode."
    Write-Host "<required> [optional]"
    Write-Host "Usage: powershell .\wss.ps1 <-l|-f> <data> [-account] [-reboot] [--help]"
    Write-Host "`tModes"
    Write-Host "`t`t-list: A list of servers, seperated by commas with no spaces inbetween"
    Write-Host "`t`t`tAliases: -l"
    Write-Host "`t`t`t[*] Example: `"ServerA.domain,ServerB.domain`""
    Write-Host "`t`t-file: A path to a file that contains one server name on each line"
    Write-Host "`t`t`tAliases: -f"
    Write-Host "`t`t`t[*] Example: `"C:\allDomainServers.txt`""
    Write-Host "`taccount: The domain and account to use. You will be prompted for a password."
    Write-Host "`t`t`tAliases: -a, -ac"
    Write-Host "`treboot: If specified, the servers will be shutdown instead of rebooted."
    Write-Host "`t`t`tAliases: -r"
    Write-Host "`thelp: Prints the help screen."
    Write-Host "`t`t`tAliases: -h, -help, /help, /?"
    Write-Host "`t`tNOTE: If no account is specified, the current user will be used."

}

Function shutdown($arr){
    $arr | ForEach{
        Write-Host "Attempting to shutdown $_"
        Stop-Computer -computername ($_) -credential ($c) -force
    }
    Write-Host "Finished. Please be aware that some servers may still be in the process of shutting down."
}

Function reboot($arr){
    $arr | ForEach{
        Write-Host "Attempting to reboot $_"
        Restart-Computer -computername ($_) -credential ($c) -force
    }
    Write-Host "Finished. Please be aware that some servers may still be in the process of rebooting."
}

#Parse Arguments
if($args.length -eq 0 -or $args[0] -eq "-help" -or $args[0] -eq "/help" -or $args[0] -eq "--help" -or $args[0] -eq "/?"){
   usage
   exit
}

for($i=0; $i -lt $args.length; $i++){
    $k = $args[$i]
    if($k -eq "-r" -or $k -eq "-reboot"){
        $reboot = $TRUE
    }elseif($k -eq "-a" -or $k -eq "-ac" -or $k -eq "-account"){
        $account = $args[++$i]
    }elseif((!$mode) -and ($k -eq "-l" -or $k -eq "-list")){
        $servers = $args[++$i]
        $mode    = "list"
    }elseif((!$mode) -and ($k -eq "-f" -or $k -eq "-file")){
        $filepath = $args[++$i]
        $mode     = "file"
    }
}

#Verify Account Credentials
$c = get-credential $account

if(!$c){
    Write-Host "No credentials specified!"
    exit
}

if($mode -eq "list"){
    Write-Host "Using Mode: List"
    if([string]::IsNullOrEmpty($servers)){
        usage
        exit
    }

    if($reboot){
        reboot $servers.split(',')
    }else{
        shutdown $servers.split(',')
    }

}elseif($mode -eq "file"){
    Write-Host "Using Mode: File"
    if([string]::IsNullOrEmpty($filepath)){
        $filepath = Read-Host 'Enter the path to the file containing a list of hosts:'
    } 

    if(!(Test-Path $filepath)){
        Write-Host "Error! File doesn't exist!"
        exit
    }

    if($reboot){
        reboot (get-content $filepath)
    }else{
        shutdown (get-content $filepath)
    }

}else{
    Write-Host "Unknown Mode! Got: $mode"
    exit
}

Edit 2: See further testing using this script:

for($i=0; $i -lt $args.length; $i++){
    Write-Host $args[$i]
    Write-Host $args[$i].GetType()
}

Powershell Prompt:

PS C:\> .\test.ps1 asdf fdsa
asdf
System.String
fdsa
System.String

PS C:\> .\test.ps1 "asdf,fdas"
asdf,fdas
System.String

PS C:\> .\test.ps1 "asdf","fdas"
asdf fdas
System.Object[]

PS C:\> .\test.ps1 asdf,fdas
asdf fdas
System.Object[]

Command Prompt:

C:\>powershell .\test.ps1 asdf fdsa
asdf
System.String
fdsa
System.String

C:\>powershell .\test.ps1 "asdf,fdas"
asdf fdas
System.Object[]

C:\>powershell .\test.ps1 "asdf","asdfa"
asdf asdfa
System.Object[]

C:\>powershell .\test.ps1 asdf,fdas
asdf fdas
System.Object[]

Notice the difference between how it treats quoted strings (test # 2). Why is this happening? And is there any way around this?

Solution 1

I was able to fix my problem by verifying that the specified argument was a string. If it was already an array, then it was just passed to the function. This is checked like so:

if($servers -is [system.string]){
        $servers = $servers.split(',')
}

Solution 2

For whatever reason, $varname contains an array when you run it in a script. And there is no Split method on an array. Can you show the script where you determine the value assigned to $varname? BTW if the array contains a string you want to split, try this $varname[0].Split(',').