Get-Content issue with -eq as string - powershell

Question

As part of a bigger script I need to verify a file contents before continuing. However, it's not working when I use | Out-String.
Note this needs to work under powershell v2 unfortunately. The file I am looking at contains the data:
{"somedata":5,"hello":[]}
If I remove | Out-String from the command then it tells me the file matches.
But if I add data to the file, then it still tells me the file matches when it doesn't. If I add | Out-String then it tells me the file doesn't match when it does...
$filecheck = Get-Content ("C:\temp\hello.txt") | Out-String
Write-Host $filecheck
if ($filecheck -eq '{"somedata":5,"hello":[]}') {
Write-Host "file matches"
} else {
Write-Host "doesn't match"
}

Answer 1

As how to fix the issue, see #tukan's answer. Anyway, for learning purposes, let's explore the root cause, namely using the Out-String cmdlet. It actually adds a newline to the string. Like so,
PS C:\temp> $filecheck = Get-Content ("C:\temp\hello.txt") | Out-String
PS C:\temp> write-host $filecheck
{"somedata":5,"hello":[]}
PS C:\temp>
As the data contains a newline, it isn't equal to the string literal used in the if statement. Thus the comparison fails. Remove the Out-String and it works:
PS C:\temp>$filecheck = Get-Content ("C:\temp\hello.txt")
PS C:\temp> $filecheck
{"somedata":5,"hello":[]}
PS C:\temp> $filecheck -eq '{"somedata":5,"hello":[]}'
True
PS C:\temp>
Earlier you noted that Out-String was needed as otherwise adding data would still make the comparison to fail. Why is that? Let's say the data in file is
{"somedata":5,"hello":[]}
{"moredata":1,"foo":bar}
What now happens is that Get-Content will give you an array of strings. The 2nd line consists of {"moredata":1,"foo":bar} plus a newline. Passing such a construct to the comparison will evaluate just the first element, thus a match.
When you pass an array to Out-String, the result is actually a string with data, newline, data and extra newline:
PS C:\temp> $filecheck|out-string
{"somedata":5,"hello":[]}
{"moredata":1,"foo":bar}
PS C:\temp>
This obviously isn't equal to the string literal used in the if statement.

Answer 2

Edit - the script will exit on first match.
Edit2 - you don't need the Else branch if nothing is found print 'failed' at the end suffice.
What about piping into Foreach-Object like this:
(Get-Content 'C:\<our_path>\test.txt') |
Foreach-Object { If ($_ -eq '{"somedata":5,"hello":[]}') {write-host 'matches'; exit}}
write-host 'failed'
I have kept your format of -eq, even thou, I would recommend regex for string/text search.