PowerShell equivalent of cmd "IF %ERRORLEVEL% NEQ 0"

Question

Looking for the PowerShell equivalent of this cmd error-check:

IF %ERRORLEVEL% NEQ 0

Here is the PowerShell code I am trying to write:

Write-Information "Installing .NET 3 from DVD:"
$NetFX3_Source = "D:\Sources\SxS"
dism /online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:$NetFX3_Source /NoRestart
IF (****TheCommandYouTellMe****) {
Write-Information "DVD not found, installing from online sources, the Win default method"
DISM.EXE /Online /Add-Capability /CapabilityName:NetFx3~~~~
Add-WindowsCapability –Online -Name NetFx3~~~~
}

Answer 1

Since dism.exe is an external program, you'd want to check the $LASTEXITCODE automatic variable:

dism /online /andsoon
if($LASTEXITCODE -ne 0)
{
    # Add your capability
}