Variable not updating when function is called

Question

I have this in my profile script.

$AddablePaths = @{
    "python3"=";C:\Python32";
    "python2"=";C:\Python27";
    "D"=";C:\D\dmd2\windows\bin";
    "gcc"=";C:\MinGW\bin";
    "verge"=";C:\Users\Cold\Dev\Verge\tools";
    "ruby"=";C:\Ruby192\bin";
    "git"=";C:\Program Files\Git\cmd";
    "cmake"=";C:\Program Files\CMake 2.8\bin";
    "emacs"=";C:\Users\Cold\Dev\emacs\bin";
    "notepad++"=";C:\Program Files\Notepad++";
    "boost-build"=";C:\Users\Cold\Dev\C++\boost-build\bin";
    "svn"=";C:\Program FIles\SlikSvn\bin";
    "gtk2"=";C:\Program Files\GTK2-Runtime\bin";
    "qt"=";C:\Qt\bin";
    "komodo"=";C:\Program Files\ActiveState Komodo Edit 6\";
    "hg"=";C:\Program Files\TortoiseHg\"
}

$AddedPaths = @()

function AddPath($keys)
{
    if ($keys.Count -eq 0) { return }

    foreach ($key in $keys)
    {
        if ($AddablePaths.Contains($key))
        {
            if (!($AddedPaths -contains $key))
            {
                $env:Path += $AddablePaths[$key]
                $AddedPaths += $key
            }
        }
        else
        {
            Write-Host "Invalid path option. Options are:"
            foreach ($key in $AddablePaths.keys) {
                Write "    $key"
            }
        }
    }
}

It's purpose is to allow me to be able to easily add to my path only the things that I need. For example, I can call AddPath("ruby","git","notepad++") to add those three things to my path. I want that it doesn't add items if I already added them, so I created the $AddedPaths array to keep track of what's been added already. However, it doesn't update when I call the function, so duplicates can still be added. What am I doing wrong?

Answer 1

You'll need to do this:

$Global:AddedPathes += $key

That should be the only place you need $Global: since it modifies it.

Answer 2

If you make it a hash table instead of an array, you don't have to scope it at all unless you re-use the same variable name in subsequent child scopes.