redirectingStreams.ps1

function Invoke-StreamData {
    [CmdletBinding()]
    param (
        [switch] $ShowWarning,
        [switch] $ShowError
    )
    
    Write-Host "This is written to the host"
    Write-Verbose "This is written to the verbose stream"
    Write-Output "This is written to the output stream"
    
    if ($ShowWarning) {
        Write-Warning "This is written to the warning stream"
    }
    
    if ($ShowError) {
        Write-Error "This is written to the error stream"
    }
}

$thisWarning = $($thisVerbose = $($thisOutput = Invoke-StreamData -ErrorVariable 'ThisError' -ErrorAction SilentlyContinue -Verbose -ShowWarning -ShowError) 4>&1) 3>&1

Write-Host ''
Write-Host "Contents of the thisWarning variable: "
Write-Host $thisWarning
Write-Host ''
Write-Host "Contents of the thisVerbose variable: "
Write-Host $thisVerbose
Write-Host ''
Write-Host "Contents of the ThisError variable: "
Write-Host $ThisError
Write-Host ''
Write-Host "Contents of the thisOutput variable: "
Write-Host $thisOutput