pwsh..Hash Filetype Array

$items = Get-ChildItem "C:\temp"

foreach($item in $items){
    $item.fullname
    $($item.Extension).Substring(1)
    #$hash.($($item.Extension).Split(".")[1])
    $hash.($($item.Extension).Substring(1))
}
$hash = @{
accdb = "Microsoft Access database file";
accde = "Microsoft Access execute-only file";
accdr = "Microsoft Access runtime database";
accdt = "Microsoft Access database template";
avi = "Audio Video Interleave movie or sound file";
bat = "PC batch file";
bin = "Binary compressed file";
bmp = "Bitmap file";
cab = "Windows Cabinet file";
cda = "CD Audio Track";
csv = "Comma-separated values file";
dif = "Spreadsheet data interchange format file";
dll = "Dynamic Link Library file";
doc = "Microsoft Word document before Word 2007";
docm = "Microsoft Word macro-enabled document";
docx = "Microsoft Word document";
exe = "Executable program file";
flv = "Flash-compatible video file";
gif = "Graphical Interchange Format file";
htm = "Hypertext markup language page";
html = "Hypertext markup language page";
ini = "Windows initialization configuration file";
iso = "ISO-9660 disc image";
jar = "Java architecture file";
jpg = "Joint Photographic Experts Group photo file";
jpeg = "Joint Photographic Experts Group photo file";
m4a = "MPEG-4 audio file";
mdb = "Microsoft Access database before Access 2007";
mid = "Musical Instrument Digital Interface file";
midi = "Musical Instrument Digital Interface file";
mov = "Apple QuickTime movie file";
mp3 = "MPEG layer 3 audio file";
mp4 = "MPEG 4 video";
mpeg = "Moving Picture Experts Group movie file";
mpg = "MPEG 1 system stream";
msi = "Microsoft installer file";
pdf = "Portable Document Format file";
png = "Portable Network Graphics file";
pot = "Microsoft PowerPoint template before PowerPoint 2007";
potm = "Microsoft PowerPoint macro-enabled template";
potx = "Microsoft PowerPoint template";
ppam = "Microsoft PowerPoint add-in";
pps = "Microsoft PowerPoint slideshow before PowerPoint 2007";
ppsm = "Microsoft PowerPoint macro-enabled slideshow";
ppsx = "Microsoft PowerPoint slideshow";
ppt = "Microsoft PowerPoint format before PowerPoint 2007";
pptm = "Microsoft PowerPoint macro-enabled presentation";
pptx = "Microsoft PowerPoint presentation";
psd = "Adobe Photoshop file";
pst = "Outlook data store";
pub = "Microsoft Publisher file";
rar = "Roshal Archive compressed file";
rtf = "Rich Text Format file";
sldm = "Microsoft PowerPoint macro-enabled slide";
sldx = "Microsoft PowerPoint slide";
swf = "Shockwave Flash file";
sys = "Microsoft DOS and Windows system settings and variables file";
tif = "Tagged Image Format file";
tiff = "Tagged Image Format file";
tmp = "Temporary data file";
txt = "Text Document";
vob = "Video object file";
vsd = "Microsoft Visio drawing before Visio 2013";
vsdm = "Microsoft Visio macro-enabled drawing";
vsdx = "Microsoft Visio drawing file";
vss = "Microsoft Visio stencil before Visio 2013";
vssm = "Microsoft Visio macro-enabled stencil";
vst = "Microsoft Visio template before Visio 2013";
vstm = "Microsoft Visio macro-enabled template";
vstx = "Microsoft Visio template";
wav = "Wave audio file";
wbk = "Microsoft Word backup document";
wks = "Microsoft Works file";
wma = "Windows Media Audio file";
wmd = "Windows Media Download file";
wmv = "Windows Media Video file";
wmz = "Windows Media skins file";
wms = "Windows Media skins file";
wpd = "WordPerfect document";
wp5 = "WordPerfect document";
xla = "Microsoft Excel add-in or macro file";
xlam = "Microsoft Excel add-in after Excel 2007";
xll = "Microsoft Excel DLL-based add-in";
xlm = "Microsoft Excel macro before Excel 2007";
xls = "Microsoft Excel workbook before Excel 2007";
xlsm = "Microsoft Excel macro-enabled workbook after Excel 2007";
xlsx = "Microsoft Excel workbook after Excel 2007";
xlt = "Microsoft Excel template before Excel 2007";
xltm = "Microsoft Excel macro-enabled template after Excel 2007";
xltx = "Microsoft Excel template after Excel 2007";
xml = "XML Document";
xps = "XML-based document";
zip = "Compressed file";
}