Yes/No - Do/While loop at the end of the script

Question

Hello !
I am kinda confused of the responses of my script.
echo "Number comparison"
do
$x = Read-Host "Please enter your first number you want to compare with"
$y = Read-Host "Please enter your second number you want to compare with"
if($x -gt $y)
echo "$x is greater than $y."
elseif($x -lt $y)
Write-Host "$x is lower than $y."
else
echo "$x is equals $y."
while (($again = Read-Host "Do you want to do it again?") -eq "No","n","N")
I have an assumption what might be the error, but I'm not really sure if it's possible to save the input of $again either in the brackets or to add {} below while. I tried but nothing was successful.
My objective is to repeat the program when it's finished, to give me/user the possibility to start it again if I type in "Y,y or yes" and stop it when I type "N,n or no". Nothing should happen if there's any other character written except
the defined ones.
greetings!

Answer 1

Do While example:
Write-Output 'Number comparison'
Do {
$x = Read-Host 'Please enter your first number you want to compare with'
$y = Read-Host 'Please enter your second number you want to compare with'
If($x -gt $y) {
Write-Output "$x is greater than $y."
} ElseIf($x -lt $y) {
Write-Output "$x is lower than $y."
} Else {
Write-Output "$x is equals $y."
$again = Read-Host 'Do you want to do it again?'
} While ($again -eq 'Yes' -or $again -eq 'y')
Do Until example:
Write-Output 'Number comparison'
Do {
$x = Read-Host 'Please enter your first number you want to compare with'
$y = Read-Host 'Please enter your second number you want to compare with'
If($x -gt $y) {
Write-Output "$x is greater than $y."
} ElseIf($x -lt $y) {
Write-Output "$x is lower than $y."
} Else {
Write-Output "$x is equals $y."
$again = Read-Host 'Do you want to do it again?'
} Until ($again -eq 'No' -or $again -eq 'n')
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