How do I create array of arrays in PowerShell?

Question

I want to create an array of arrays in PowerShell.

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

It works fine. However, sometimes I have only one a

Answer 1

Adding a comma force to create an array:

$x = @(
    ,@(1,2,3)
)

Simple way:

$x = ,(1,2,3)