Powershell Reading text file word by word - arrays

Question

So I'm trying to count the words of my text file however when I do get-content the array reads them letter by letter and so it doesn't let me compare them word by word. I hope you guys can help me out!
Clear-Host
#Functions
function Get-Articles (){
foreach($Word in $poem){
if($Articles -contains $Word){
$Counter++
}
}
write-host "The number of Articles in your sentence: $counter"
}
#Variables
$Counter = 0
$poem = $line
$Articles = "a","an","the"
#Logic
$fileExists = Test-Path "text.txt"
if($fileExists) {
$poem = Get-Content "text.txt"
}
else
{
Write-Output "The file SamMcGee does not exist"
exit(0)
}
$poem.Split(" ")
Get-Articles

Answer 1

What your script does, edited down a bit:
$poem = $line # set poem to $null (because $line is undefined)
$Articles = "a","an","the" # $Articles is an array of strings, ok
# check file exists (I skipped, it's fine)
$poem = Get-Content "text.txt" # Load content into $poem,
# also an array of strings, ok
$poem.Split(" ") # Apply .Split(" ") to the array.
# Powershell does that once for each line.
# You don't save it with $xyz =
# so it outputs the words onto the
# pipeline.
# You see them, but they are thrown away.
Get-Articles # Call a function (with no parameters)
function Get-Articles (){
# Poem wasn't passed in as a parameter, so
foreach($Word in $poem){ # Pull poem out of the parent scope.
# Still the original array of lines. unchanged.
# $word will then be _a whole line_.
if($Articles -contains $Word){ # $articles will never contain a whole line
$Counter++
}
}
write-host "The number of Articles in your sentence: $counter" # 0 everytime
}
You probably wanted to do $poem = $poem.Split(" ") to make it an array of words instead of lines.
Or you could have passed $poem words into the function with
function Get-Articles ($poem) {
...
Get-Articles $poem.Split(" ")
And you could make use of the PowerShell pipeline with:
$Articles = "a","an","the"
$poemArticles = (Get-Content "text.txt").Split(" ") | Where {$_ -in $Articles}
$counter = $poemArticles | Measure | Select -Expand Count
write-host "The number of Articles in your sentence: $counter"

Answer 2

TessellatingHeckler's helpful answer explains the problem with your approach well.
Here's a radically simplified version of your command:
$counter = (-split (Get-Content -Raw text.txt) -match '^(a|an|the)$').count
write-host "The number of articles in your sentence: $counter"
The unary form of the -split operator is key here: it splits the input into words by any run of whitespace between words, resulting in an array of individual words.
-match then matches the resulting array of words against a regex that matches words a, an, or the: ^(a|an|the)$.
The result is the filtered subarray of the input array containing only the words of interest, and .count simply returns that subarray's count.