
Just toss out the unwanted expression result with `Out-Null`.:

    $person | Select-Object 'FirstName', 'LastName',
                 @{
                     Name="FullName";
                     Expression= {
                         "test" -eq "example" | out-null
                        return "$($_.FirstName) $($_.LastName)"
                     }
                 }



In PS, when using [`Select-Object`][1], the `-Property` param "specifies the properties to select":

> The value of the Property parameter can be a new *calculated property*. To create a calculated, property, use a hash table.
>
> Valid keys are:  
>
> * **Name**: `<string>`  
> * **Expression**: `<string>` or `<script block>`

As an starting point, here's an [anonymous object][2]

```cs
$person = [pscustomobject]@{
    FirstName = "Kyle";
    LastName = "Mit"
}
```

The following calculated property works just fine:

```cs
$person | Select-Object 'FirstName', 'LastName', 
            @{
                Name="FullName";
                Expression= { "$($_.FirstName) $($_.LastName)" }
            }
```

Which correctly returns the following:

```none
FirstName LastName FullName
--------- -------- --------
Kyle      Mit      Kyle Mit
```

**However**, I'm trying to build a calculated property that takes some complicated logic and requires multiple lines to implement.  As soon as I have another return value inside the expression both values are returned.  

So the following query will return `FullName` as `{ false, "Kyle Mit" }`

```cs
$person | Select-Object 'FirstName', 'LastName', 
            @{
                Name="FullName";
                Expression= { 
                    "test" -eq "example"
                    return "$($_.FirstName) $($_.LastName)" 
                }
            }
```

Which returns the following:

```none
FirstName LastName FullName         
--------- -------- --------         
Kyle      Mit      {False, Kyle Mit}
```

But I'm attempting to explicitly return just the last statement.  Delimiting with `;` or using `return` doesn't seem to help.  

Any ideas?

[1]: https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/select-object?view=powershell-7#parameters
[2]: https://stackoverflow.com/a/56813241/1366033