Replace values in hashtable in PowerShell - powershell

Question

I have a hashtable in PowerShell that looks like this:
$table = #{
1 = 3;
2 = 3;
5 = 6;
10 = 12;
30 = 3
}
I need to replace all "3" values with "4".
Is there a nice and clean way to do this without iterating over each pair and writing each one to a new hashtable?
Could the action with the same data be done easier if I'd use some other .NET collection class?
This throws exception that "Collection was modified":
$table.GetEnumerator() | ? {$_.Value -eq 3} | % { $table[$_.Key]=4 }
This adds another "Values" member to the object and breaks it:
$table.Values = $table.Values -replace 3,4

Answer 1

You can't modify the table while iterating over it, so do the iteration first and then do the updates. Just split your pipeline in two:
PS>$change = $table.GetEnumerator() | ? {$_.Value -eq 3}
PS>$change | % { $table[$_.Key]=4 }
PS>$table
Name Value
---- -----
30 4
10 12
5 6
2 4
1 4

Answer 2

The above answer didn't work for me and I couldn't fit this as a comment. The above single-lined answer didn't do anything. I am trying to change a single value to "Off" based on my hashtable.Key aka Name. Notice where I wrote $(backtick) is supposed to be a literal backtick, but it was messing up the code block. Here is my hashtable that is pulled from .\BeepVariables.txt.
Name Value
---- ----
$varAwareCaseSound "On"
$varEmailSound "On"
function SetHash2([string]$keyword, [string]$value){
$hash = #{}
$hash = (get-content .\BeepVariables.txt).replace(";"," $(backtick) n") | ConvertFrom-StringData
#($hash.GetEnumerator()) | ?{$_.key -like "*$keyword*"} | %{$hash[$_.value]=$value}
$hash
}
SetHash2 "aware" '"Off"'