Compare Object Powershell

Question

I want to compare two objects and get only the different values. I have this code:

$a = ("this is blah blah DOG")
$b = ("Dit is blah BLAH dog")
Compare-Object -ReferenceObject $a -DifferenceObject $b

with the above code I get the following output:

InputObject           SideIndicator
-----------           -------------
Dit is blah BLAH dog  =>           
this is blah blah DOG <=    

However I want only the different values in both the objects i.e. Dit and this

Answer 1

You don't show what your csv file looks like, so, there's that, but stepping though what you are after.

($a = Get-Content -Path 'D:\Documents\file1.txt')
($b = Get-Content -Path 'D:\Documents\file2.txt')
Compare-Object -ReferenceObject $a -DifferenceObject $b

<#
What's in the two files

file1
hello
world



file2
hello
world



InputObject SideIndicator
----------- -------------
file2       =>           
file1       <=           
#>




($a = Get-Content -Path 'D:\Documents\file1.csv')
($b = Get-Content -Path 'D:\Documents\file2.csv')
Compare-Object -ReferenceObject $a -DifferenceObject $b

<#
What's in the two files

Col1,Col2,Col3
file1,hello,world



Col1,Col2,Col3
file2,hello,world



InputObject       SideIndicator
-----------       -------------
file2,hello,world =>           
file1,hello,world <=           
#>



($a = (Get-Content -Path 'D:\Documents\file1.csv' | Select -Skip 1) -split ',')
($b = (Get-Content -Path 'D:\Documents\file2.csv' | Select -Skip 1) -split ',')
Compare-Object -ReferenceObject $a -DifferenceObject $b

<#
file1
hello
world



file2
hello
world




InputObject SideIndicator
----------- -------------
file2       =>           
file1       <=  
#>

Lastly, this also sounds eerily like this Q&A

Compare two lists in Powershell

Answer 2

Compare-Object works on the whole objects and its properties. It will not do lazy string matching. If you wanted that you need to split the string into arrays first

$a = "this is blah blah DOG".Split()
$b = "Dit is blah BLAH dog".Split()
Compare-Object -ReferenceObject $a -DifferenceObject $b

Beware of potential issues with case sensitivity and use the -CaseSensitive as needed.

Answer 3

For this specific example:

$a = ("this is blah blah DOG").Split(" ")
$b = ("Dit is blah BLAH dog").Split(" ")
Compare-Object -ReferenceObject $a -DifferenceObject $b