Comparing two arrays & get the values which are no

问题:

i wanted a small logic to compare contents of two arrays & get the value which is not common amongst them using powershell

example if

$a1=@(1,2,3,4,5)
$b1=@(1,2,3,4,5,6)

$c which is the output should give me the value "6" which is the output of what's the uncommon value between both the arrays.

Can some one help me out with the same! thanks!

回答1:

PS > $c = Compare-Object -ReferenceObject (1..5) -DifferenceObject (1..6) -PassThru
PS > $c
6

回答2:

$a = 1,2,3,4,5
$b = 4,5,6,7,8

$Yellow = $a | Where {$b -NotContains $_}

$Yellow contains all the items in $a except the ones that are in $b:

PS C:\> $Yellow
1
2
3

$Blue = $b | Where {$a -NotContains $_}

$Blue contains all the items in $b except the ones that are in $a:

PS C:\> $Blue
6
7
8

$Green = $a | Where {$b -Contains $_}

Not in question, but anyways; Green contains the items that are in both $a and $b.

PS C:\> $Green
4
5

回答3:

Look at Compare-Object

Compare-Object $a1 $b1 | ForEach-Object { $_.InputObject }

Or if you would like to know where the object belongs to, then look at SideIndicator:

$a1=@(1,2,3,4,5,8)
$b1=@(1,2,3,4,5,6)
Compare-Object $a1 $b1

回答4:

Your results will not be helpful unless the arrays are first sorted. To sort an array, run it through Sort-Object.

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

Compare-Object -ReferenceObject ($x | Sort-Object) -DifferenceObject ($y | Sort-Object)

回答5:

Try:

$a1=@(1,2,3,4,5)
$b1=@(1,2,3,4,5,6)
(Compare-Object $a1 $b1).InputObject

Or, you can use:

(Compare-Object $b1 $a1).InputObject

The order doesn't matter.

回答6:

This should help, uses simple hash table.

$a1=@(1,2,3,4,5) $b1=@(1,2,3,4,5,6)


$hash= @{}

#storing elements of $a1 in hash
foreach ($i in $a1)
{$hash.Add($i, "present")}

#define blank array $c
$c = @()

#adding uncommon ones in second array to $c and removing common ones from hash
foreach($j in $b1)
{
if(!$hash.ContainsKey($j)){$c = $c+$j}
else {hash.Remove($j)}
}

#now hash is left with uncommon ones in first array, so add them to $c
foreach($k in $hash.keys)
{
$c = $c + $k
}