Finding the length of an array

Using the ".length" will only correctly give the number of items in an array of there is more that one item.
If the item has one item this method will fail.

$a = ls *.bak|foreach {$_.name}
# Replace above with below
$a = @($a = ls *.bak|foreach {$_.name})

Not sure about the above syntax.
Below the $roy.length gives no output but $dd.length gives a value of "1"

PS C:\scripts> $roy.length
PS C:\scripts>
PS C:\scripts> $roy.samaccountname
abcde001
PS C:\scripts> $dd = @( $roy.samaccountname)
PS C:\scripts> $dd.length
1