Pass parameter from one Powershell function to another - powershell

Question

I’m new to powershell and development in general. I’m trying to write a script that will email a contact once a file exceeds a certain size. I have two individual functions both working separately (one to check the file size and one to generate a file for sendmail to use) but I can’t get them to interact.
I want to execute the function CheckSize and if the variable $ExceedsSize gets set to 1 then call function SendMail otherwise the script should finish with no other action.
I’ve searched through the forums but couldn’t find anything to apply to what I’m doing.
##Check file to see if it is over a particular size and then send email once threshold is reached.
param(
[string]$SiteName = "TestSite", #Name of Site (No Spaces)
[string]$Path = "\\NetworkPath\Directory", #Path of directory to check
[int]$FileSizeThreshold = 10, #Size in MB that will trigger a notification email
[string]$Contacts = "MyEmail#email.com"
)
CLS
##Creates variable $ExceedsSize based on newest file in folder.
Function CheckSize {
IF ((GCI $Path -Filter *.txt | Sort LastWriteTime -Descending | Select-Object -first 1 | Measure-Object -property Length -sum).sum / 1000000 -gt $FileSizeThreshold) {$ExceedsSize = 1}
ELSE {$ExceedsSize = 0}
Write-Host $ExceedsSize
}
Function SendMail {
Param([string]$Template, [string]$Contacts, [string]$WarnTime)
$EmailLocation = "\\NetworkPath\Scripts\File_$SiteName.txt"
#Will Generate email from params
New-Item $EmailLocation -type file -force -value "From: JMSIssue#emails.com`r
To: $Contacts`r
Subject: $SiteName file has exceeded the maximum file size threshold of $FileSizeThreshold MB`r`n"
#Send Email
#CMD /C "$SendMail\sendmail.exe -t < $EmailLocation"
}

Answer 1

Add this before or after your Write-Host $ExceedsSize:
return $ExceedsSize
Add this to the bottom:
$var = CheckSize
if ($var -eq 1){
SendMail
}
Explanation
You have two functions, but don't actually run them. The part at the bottom does that.
Your CheckSize function does not return the $ExceedsSize for the rest of the function; by default it remains within the scope of the function. return x means the variable is passed back to the main script. $var = means it is assigned ot that variable.

Answer 2

Per the other answer, you need to return $ExceedsSize instead of using Write-Host (see here for why Write-Host is considered harmful: http://www.jsnover.com/blog/2013/12/07/write-host-considered-harmful/).
You could alternatively call the SendMail function from within the CheckSize function, e.g:
if ($ExceedsSize -eq 1){SendMail}
You will still need to call the CheckSize function somewhere also:
CheckSize
You might also want to give consideration to naming your functions in the verb-noun style of the built in cmdlets. This really helps make their use more explicit to you and others. When choosing a verb, its best to stick to the approved list: https://msdn.microsoft.com/en-us/library/ms714428(v=vs.85).aspx
And also to use names that are fairly unique to avoid possible conflicts.
I'd suggest something along the lines of:
Get-NewestFileSize
(although that's what it should then return)
and
Send-CCSMail