Powershell break a long array into a array of array with length of N in one line?

Question

For example, given a list 1,2,3,4,5,6,7,8,1,2,3,4,5,6,7,8 and a number 4, it returns a list of list with length of 4, that is (1, 2, 3, 4), (5, 6, 7, 8),

Answer 1

$a = 1,2,3,4,5,6,7,8,1,2,3,4,5,6,7,8,0
$b = 0..([Math]::ceiling($a.Length / 4) - 1) | 
    % {  @(, $a[($_*4)..($_*4 + 4 - 1)]) } 

Don't know why I had to put a comma after (.