Powershell Compare Two Strings - powershell

Question

cls
$logFile = "C:\test\output1.txt"
Function LogWrite
{
Param ([string]$logstring)
Add-content $Logfile -value $logstring
}
LogWrite "DocumentID|Correct|Wrong|UDI|Number of Errors|Line Number"
LogWrite "------------------------------------------"
$file = "C:\test\test\Birth records evt logging.txt"
$pattern = "^(.*)`t(.*)`t(.*)`t(.*)`t(.*)`t(.*)`t(.*)`t(COB Reviewed)$"
$pattern2 = "^(.*)`t(.*)`t(.*)`t(.*)`t(.*)`t(.*)`t(.*)`t(DocSecID)$"
$pattern3 = "^(.*)`t(.*)`t(.*)`t(.*)`t(.*)`t(.*)`t(.*)`t(.*)$"
$errorCountTotal = 0
$linecount = 0
$line2Count = 0
Get-Content $file|
ForEach-Object{
$errorCountLine = 0
$linecount++
$transposition = $false
if($_ -match $pattern){
}elseif($_ -match $pattern2){
}elseif($_ -match $pattern3){
$line2Count++
if($matches[6].Length -eq $matches[7].length){
$wrong = $matches[6]
$correct = $matches[7]
$documentID = $matches[3]
$UDI = $matches[8]
$a = [char[]]$Matches[6]
$b = [char[]]$matches[7]
# for($i = 0; $i -lt $a.Length; $i++){
# for($x = 1; $x -lt $a.Length; $x++){
# if($a[$i] -eq $b[$i+$x] -and $a[$i+$x] -eq $b[$i]){
# if($a[$i] -eq $a[$i+$x]){
# write-host "same letter"
# }else{
# $errorCountLine += 2
# }
# }
# }
#}
#Compare-Object $a $b |Format-List |Out-File "C:\test\test3.txt"
$errorCountLine += (#(Compare-Object $a $b -SyncWindow 0).count /2)
$errorCountTotal +=$errorCountLine
Write-Host $matches[6] " - " $matches[7] " - " $errorCountLine " - " $linecount
Write-Host $errorCountTotal
LogWrite "$documentID|$wrong|$correct|$UDI|$errorCountLine|$linecount"
}else{
$a = [char[]]$Matches[6]
$b = [char[]]$matches[7]
for($i = 0; $i -lt $a.Length; $i++){
for($x = 1; $x -lt $a.Length; $x++){
if($a[$i] -eq $b[$i+$x] -and $a[$i+$x] -eq $b[$i]){
if($a[$i] -eq $a[$i+$x]){
# write-host "same letter"
}else{
$errorCountLine += 2
}
}
}
}
$diffL = [math]::Abs($Matches[7].Length - $Matches[6].Length)
$errorCountLine = (((#(Compare-Object $a $b).count-$diffL) /2) + $diffL)
$test = #(Compare-Object $a $b).count
$errorCountTotal += $errorCountLine
Write-Host $matches[6] " - " $matches[7] " - " $errorCountLine " - " $linecount
$wrong = $matches[6]
$correct = $matches[7]
$documentID = $matches[3]
$UDI = $matches[8]
LogWrite "$documentID|$wrong|$correct|$UDI|$errorCountLine|$linecount"
Write-Host $errorCountTotal
}
}
}
Write-Host $line2Count #number of lines that the program looks at. passes through pattern3.
LogWrite `n
LogWrite "The total number of errors is $errorCountTotal"
I need to compare the contents of two Strings with this program. Above is what i have so far. The only problem is it tells me whether or not the two strings match or not(0 or -1) character by character in the string. Midred and Mildred would come up as 5 errors when in fact it needs to be only 1 error. i cannot just compare the strings as a whole either because there could be multiple errors in a string. any ideas would be great.

Answer 1

Try using Compare-Object on the character arrays:
$a = [char[]]'Mildred'
$b = [char[]]'Midred'
Compare-Object $a $b
InputObject SideIndicator
----------- -------------
l <=
#(Compare-Object $a $b).count
1

Answer 2

Why not just compare the two strings, e.g.
$matches[6] -ne $ matches [7]
?