Extracting data from the $matches hashtable after a Powershell Regeg -match

Question

I've already spent over an hour trying to get a simple RegEx to work. My pattern is working, and I'm getting back the $Matches which as I have read is supposed to be a hash table. So how do I get what I've captured?

Code:

   cls 
   $keyword = "this is a 12345 test" 
   $pattern = "\d{5}"
   $keyword -match $pattern 
   $returnZipcode = "ERROR" 
   Write-Host "GetZipCodeFromKeyword RegEx `$Matches.Count=$($Matches.Count)" 
   $Matches | Out-String | Write-Host
   Write-Host "`$Matches[0].Value=$($Matches[0].Value)"
   Write-Host "`$Matches.Get_Item('0')=$($Matches.Get_Item("0"))"
   if ($Matches.Count -gt 0) 
      {
         $returnZipcode = $Matches[0].Value
      }

   # this is how hash tables work - why doesn't same work with the $Matches variable? 
   $states = @{"Washington" = "Olympia"; "Oregon" = "Salem"; California = "Sacramento"}
   $states | Out-String | Write-Host
   Write-Host "`$states.Get_Item('Oregon')=$($states.Get_Item("Oregon"))"

Run time results:

Name                           Value  
----                           -----  
0                              12345  

$Matches[0].Value=
$Matches.Get_Item('0')=

Name                           Value
----                           -----
Washington                     Olympia
Oregon                         Salem  
California                     Sacramento 

$states.Get_Item('Oregon')=Salem

score 3 · Accepted Answer · answered Nov 28 '14 at 18:13

$Matches is just a hashtable, the Name and Value columns aren't properties of the elements. Name is just the key, Value is the value.

PS C:\> $Matches

Name                           Value
----                           -----
0                              12345


PS C:\> $Matches[0]
12345

If you wish you can use Get_Item, but the key in $Matches is an integer, not a string:

PS C:\> $states.Get_Item('Oregon')
Salem
PS C:\> $Matches.Get_Item(0)
12345

Unlike some other languages not all hashtable keys have to be strings and Powershell mostly won't convert numbers to and from strings unless you tell it to.

Thanks, just posted follow-up here: http://stackoverflow.com/questions/27194148/powershell-match-in-function-gets-extra-true-false-when-returned I thought the true/false was coming back as part of hashtable, still not sure why. — NealWalters, Nov 28 '14 at 18:22

Extracting data from the $matches hashtable after a Powershell Regeg -match

1 Answers1