Declaring the splat is useful for reusing sets of parameters multiple times or with slight variations:
$splat = @{
Class = "Win32_SystemEnclosure"
Property = "Manufacturer"
ErrorAction = "Stop"
}
Get-WmiObject -ComputerName $env:COMPUTERNAME @splat
Get-WmiObject -ComputerName "Computer2" @splat
Get-WmiObject -ComputerName "Computer3" @splat
However, if the splat is not indented for reuse, you may not wish to declare it. It can be piped instead:
@{
ComputerName = $env:COMPUTERNAME
Class = "Win32_SystemEnclosure"
Property = "Manufacturer"
ErrorAction = "Stop"
} | % { Get-WmiObject @_ }