Flattening nested arrays in Powershell

Question

Given this input:

$values = @(1, @(2, 3), $null, @(@(4), 5), 6)

What is necessary to create a clean iteration/pipeline over

1,2,3,4,5,6

?

Conditions:

• It should not include $null in the output.
• It should result in an empty array even if the input is $null or all of the input's values are $null.

Bonus:

• It should show [1,2,3,4,5,6] as the result of ConvertTo-Json -Compress
• It should preferably be clean and memorable, i.e. non-byzantine pipe manipulation preferred, no dependency on custom functions, if that is at all possible.

I've seen Flatten array in PowerShell, the solutions there do not seem to fulfill the conditions.

Answer 1

@(1, @(2, 3), $null, @(@(4), 5), 6) | %{$_} | ?{$_ -ne $null}

The output:

1
2
3
4
5
6

The ForEach-Object cmdlet (%) flattens arrays by default.