Getting Missing element from comparison of Array's using powershell

Question

Possible Duplicate:
Comparing two arrays & get the values which are not common

I wanted a logic to get uncommon items from an array, for example:

$a=@(1,2,3,4,5,6)
$b=@(1,2,3,4,5,7,9,10)

I want the output $c to be 6 which is the missing element in $b array, priority should be only given to the array contents of $a.

Can anyone please help me out with this?
Thanks!

Check my comment on your previous question, you will find (with a little effort). — stej, Jun 16 '11 at 08:22
hi @stej its not a duplicat question, i want preference to be given to array $a now — PowerShell, Jun 16 '11 at 09:00

score 5 · Accepted Answer · answered Jun 16 '11 at 09:35

5

Either empo's approach, or

$a1=@(1,2,3,4,5,8)
$b1=@(1,2,3,4,5,6)
Compare-Object $a1 $b1 | 
   Where-Object { $_.SideIndicator -eq '<=' } | 
   Foreach-Object { $_.InputObject }

returns 8

answered Jun 16 '11 at 09:35

stej

Emiliano Poggi · Answer 2 · 2011-06-16T10:06:45.457

4

$c = $a | ? {!($b -contains $_)}

The priority will be given to the variable you "pipe".

edited Jun 16 '11 at 10:06

answered Jun 16 '11 at 09:29

Emiliano Poggi

1

You could also use: ?{$b -notcontains $_} – Rynant Jun 16 '11 at 12:06
Or `? { -not ($b -contains $_) }`, the result is the same. – Emiliano Poggi Jun 16 '11 at 12:38

2 Answers2