how to sum integer output function to a value - function

Question

Good evening. I'm totally newbie to powershell and I have surely a silly question but I can't find an answer on my own.
I have a txt file like this
192.168.1.1|2
192.168.1.2|4
192.168.1.3|3
My function takes an IP as a parameter and it returns the integer values after the pipe. The function works but I don't know how to sum a value to the function result.
$client = "192.168.1.2"
function file-update($client) {
$clientrow = gc "C:\clients.txt" | ? {$_ -match $client}
if ($clientrow) {
$filesupdated = $clientrow.Split("|")[1]
return $filesupdated
}
else {
return 0
}
}
file-update $client
# it returns 4
file-update $client + 1
# it returns 4 too instead of 5
What'is my mistake?
Thanks in advance.

Answer 1

You need your function to execute and return a value before performing the addition. You can simply use () to group the function call. Since your function returns a [string] when a client is found, you will have to do a conversion to a numeric type to support addition. Having an integer on the left-hand side (LHS) of the operator (+) will convert the RHS value to [int] automatically if possible.
1 + (file-update $client)
You can write the function differently to minimize the amount of work done to extract the integer value:
# Best practice is to use verb-noun for naming functions
# Added file parameter (for file path) to not hard code it inside the function
function Update-File {
Param(
$client,
$file
)
# Casting a null value to [int] returns 0
# Delimiter | to override default ,
# Named headers are needed since the file lacks them
[int](Import-Csv $file -Delimiter '|' -Header IP,Number |
Where IP -eq $client).Number
}
$client = '192.168.1.2'
$file = 'c:\clients.txt'
Update-File $client $file # returns 4
(Update-File $client $file) + 1 # returns 5