Compare Objects In Single PowerShell Array

Question

I've searched but I can only find posts comparing two different arrays in PowerShell. What I'm trying to do is compare the contents within a single array to see if everything inside is equal (e.g.; 2,2,2,2 = true; 2,2,2,3 = false). Does anyone have any ideas how this might be accomplished? Thanks.

Answer 1

You can make use of Get-Unique

$array = @(2, 2, 2, 2)

if (($array | Get-Unique).Count -gt 1) {
    Write-Host "some odd ones"
} else {
    Write-Host "all the same"
}

It will count how many unique items exist in the array

We pass that result to be evaluated by the if statement

If there is more than one unique result from Get-Unique, we know that all elements are not equal

Check the SS64 page

Answer 2

You can try something like this which iterates through element and compares it to the last to make sure that they are all equal.

You could make a function out of this logic that takes an array as a parameter and returns either $true or $false so that you can reuse. You may also be able to improve upon it by breaking out of the loop if you find something that is not equal.

$arr = (2,2,2,3)

$notEqual = $false;

for ($i = 1; $i -lt $arr.Length; $i++)
{
  if ($arr[$i] -ne $arr[$i-1]) {$notEqual = $true}
}

if ($notEqual)
{
    Write-Host "Array elements not equal"
}
else
{
    Write-Host "Array members are qual"
}