odd.ps1

   function one {[cmdletbinding()]param()
        begin {Write-Host "one begins"}   end {Write-host "one ends"}
        process {1,2,3}
    }
    function two {param ([parameter(ValueFromPipeline)]$p)
        begin {Write-Host "two begins"}   end {Write-host "two ends"}
        process {
            if ($p -eq 2) {$p / 0 } # cause a division by zero error
            $p
        }
    }
    function three {param ([parameter(ValueFromPipeline)]$p)
        begin {Write-Host "three begins"} end {Write-host "three ends"}
        process {
            Write-host "three Processed $p"
            $p
        }
    }
    function four {[cmdletbinding()]param()
        begin {Write-Host "four begins"}  end {Write-host "four ends"}
        process {
            $result = one | two | three
            Write-host "And the result is "
            $result
        }
    }
four
    function four {[cmdletbinding()]param()
        begin {Write-Host "four begins"}  end {Write-host "four ends"}
        process {   # Add try {} Catch {}
                try { $result = one | two | three} catch {Write-Host "Error in the pipeline"}
                Write-host "And the result is "
                $result
        }
    }
four
 try {  one | two | three} catch {Write-Host "Error in the pipeline"}
    function five {param ($p) two  $P}
    function six  {param ($p) five $P}
    try {six 2} catch {"error happened"}
    function four {[cmdletbinding()]param()
        begin {Write-Host "four begins"}  end {Write-host "four ends"}
        process { #remove try {} / catch and use -ErrorAction Stop
                Write-Host "Error action preference in four is $errorActionPreference"
                $result = one | two -ErrorAction Stop | three  
                Write-host "And the result is "
                $result
        }
    }
four
four -ErrorAction SilentlyContinue
 four -ErrorAction Stop
    try {2/0}                                      catch {"Bad calculation"}
    try {Start-Sleep ([timespan]::FromDays(30)) }  catch {"Bad timespan"}    # not in 7.2.x or earlier
    try {Get-Item "Nonexistent" }                  catch {"Bad item"}
    function two {param ([parameter(ValueFromPipeline)]$p )
        begin {Write-Host "two begins"}   end {Write-host "two ends"}
        process { # change the cause of the error
            if ($p -eq 2) {Get-Item "NonExistent" -ErrorAction Stop}
            $p
        }
    }
    function four {[cmdletbinding()]param()
        begin {Write-Host "four begins"}  end {Write-host "four ends"}
        process { # back to no error action or try/catch
            Write-host "Error action preference in four is $ErrorActionPreference"
            $result = one | two | three
            Write-host "And the result is "
            $result
        }
    }
four
    function two {param ([parameter(ValueFromPipeline)]$p )
        begin {Write-Host "two begins"}   end {Write-host "two ends"}
        process { # remove -ErrorAction stop 
            if ($p -eq 2) {Get-Item "NonExistent"}
            $p
        }
    }
    function four {[cmdletbinding()]param()
        begin {Write-Host "four begins"}  end {Write-host "four ends"}
        process { #  use -ErrorAction Stop
                Write-host "Error action preference in four is $ErrorActionPreference"
                $result = one | two -ErrorAction Stop | three  
                Write-host "And the result is "
                $result
        }
    }
four
    function seven {[cmdletbinding()]param()
        begin {Write-Host "seven begins"}  end {Write-host "seven ends"}
        process { # create an error record, which contains an exception, then throw it.
            $ex = [System.Exception]::new("This is not the result you are looking for")
            $er = [System.Management.Automation.ErrorRecord]::new(
                $ex, "42", [System.Management.Automation.ErrorCategory]::OperationStopped, $null) 
            $PSCmdlet.ThrowTerminatingError($er)
        }
    }
    function four {[cmdletbinding()]param()
        begin {Write-Host "four begins"}  end {Write-host "four ends"}
        process { # back to no error action or try/catch
            Write-host "Error action preference in four is $ErrorActionPreference"
            $result = one | two | three
            Write-host "And the result is "
            $result
        }
    }
    function two { param ([parameter(ValueFromPipeline)]$p )
        begin {Write-Host "two begins"}   end {Write-host "two ends"}
        process {
            if ($P -eq 2) {seven}
            $p
        }
    }
four
    function two { param( [parameter(ValueFromPipeline)]$p )
        begin {Write-Host "two begins"}   end {Write-host "two ends"}
        process {
            if ($p -eq 2) {
                $ex = [System.Exception]::new("A different error")
                $er = [System.Management.Automation.ErrorRecord]::new($ex, "42",
                    [System.Management.Automation.ErrorCategory]::OperationStopped, $null)
                $PSCmdlet.ThrowTerminatingError($er)
                }
                $p
            }
        }
four
    function two { param( [parameter(ValueFromPipeline)]$p )
        begin {Write-Host "two begins"}   end {Write-host "two ends"}
        process {
            if ($p -eq 2) {
                $ex = [System.Exception]::new("A different error")
                $er = [System.Management.Automation.ErrorRecord]::new($ex, "42",
                    [System.Management.Automation.ErrorCategory]::OperationStopped, $null)
                throw $er
            }
            $p
        }
    }
fourr
four
    function five {[cmdletbinding()] param ($p) 
        Write-host "Error action preference in five is $ErrorActionPreference"
        Two  $P -ErrorAction continue ; 
        "Five done"
    }
five 2
five 2 -ErrorAction SilentlyContinue
$x = one | two -ErrorAction SilentlyContinue | three
$ErrorActionPreference =  [System.Management.Automation.ActionPreference]::break
get-item 'nonexistent'
$ErrorActionPreference =  [System.Management.Automation.ActionPreference]::Inquire
get-item 'nonexistent'
get-item 'nonexistent' -erroraction stop
$ErrorActionPreference =  [System.Management.Automation.ActionPreference]::break
get-item 'nonexistent' -errorAction stop
q
q
$ErrorActionPreference =  [System.Management.Automation.ActionPreference]::SilentlyContinue
throw
pwsh.exe -command 'echo "Hello world"'
pwsh.exe -command "echo 'Hello world'"
Get-Unique -?
Get-Command Get-Unique
@{ 42 = 'foo1' }.42
[pscustomobject]@{ 42 = 'foo1' }
$psco = [pscustomobject]@{ 42 = 'foo1' }
$Psco.42
$h = @{ 42 = 'foo1' }
$h.42
$h = (@{ "42" = 'foo1' })
$h.42