Powershell function not executing as expected - powershell

Question

I have the following function that shows if any of the words in an array are contained in a string:
function AnyOf ([string] $line, [string[]] $list)
{
Write-Output "AnyOf!"
foreach($item in $list)
{
if($line.Contains($item))
{
Write-Output "Found: $item"
return $true
}
}
return $false
}
And this to test it:
function main
{
[string[]]$a = #("user1", "user2")
$str = "user1 and user2"
$res = AnyOf($str, $a)
}
I expect it to see both user1 and user2 to get printed out but nothing is printed. It appears as though the function isn't getting called because the Write-Output "AnyOf!" is never executed.
However, when I execute:
AnyOf($str, $a)
Instead of:
$res = AnyOf($str, $a)
I can see that the function is called but the iteration doesn't seem to happen... What am I doing wrong?

Answer 1

A few things,
First of all, functions in powershell are not called using () you would call the function as
AnyOf $str $a
The standard convention is $<<nameOfFunction>> <<param1>> <<param2>>
Secondly, your output is being captured in $res and therefore not printed to the screen, if you add $res at the end of your main function it will output.
So your main function becomes:
function main
{
[string[]]$a = #("user1", "user2")
$str = "user1 and user2"
$res = AnyOf $str $a
$res #or just don't assign it to $res..
}
#to call main:
main
Output:
AnyOf!
Found: user1
True
As you can see in the above output it never finds User2 because you use a return $true once it finds a match, exiting out of the function.
Another thing to note is that when you return $false or $true these actually become part of the output stream, which might not be what you want as it can lead to unexpected behavior.