PowerShell: Array Sub-Expression Operator @(...) (Collection to Array)

Array can be created by the Array Sub-Expression Operator. It has the syntax

@(…)

it forces the result to be an array.

$x = @(3, 4, 5)

# create a empty array
$x = @();
$x.length

It is often used to turn a collection into an Array.

@(command)

# turn dir result into an array, and use array method length to get count
@(dir).length