if/elseif not working right - powershell

Question

I have a script that checks how much memory the top w3wp process is using. Then depending on how close to 1 gig it is using, it will give out a message.
param($warn, $crit)
$LastExitCode = 3
$Output1 = ""
$output = ""
$myW3WP = Get-Process w3wp | Sort -Descending WS | select -first 1 |
Measure-Object WS -Sum
$myW3WP = ("{0:N2} " -f ($myW3WP.sum / 1mb))
$myW3WP.trim()
if ($myW3WP -gt $crit) {
$LastExitCode = 2
$output1 = "CRITICAL: Memory for W3WP has passed 1 gig $myW3WP"
$output = $output1
} elseif ($myW3WP -gt $warn) {
$LastExitCode = 1
$output1 = "WARN: Memory for W3WP is getting close to 1 gig $myW3WP"
$output = $output1
} else {
$LastExitCode = 0
}
$output = $output1
Write-Host $output $LastExitCode "$myW3WP >= " $crit ($myW3WP -gt $crit) "$myW3WP >= " $warn ($myW3WP -gt $warn)
$myW3WP = ""
In values for $crit is 1000 and the value for $warn is 900.
(Note: the Write-Host line is like that for troubleshooting)
Here is the output I am getting:
CRITICAL: Memory for W3WP has passed 1 gig 161.03 2 161.03 >= 1000 True 161.03 >= 900 False
The 161.03 is the megs of RAM being used.
Any ideas on why it is saying 161.03 is greater than 1000?

Answer 1

Don't compare apples and oranges!
You'll need a numerical value if you want to compare it to other numerical values
When you call:
$myW3WP = ("{0:N2} " -f ($myW3WP.sum / 1mb))
$myW3WP.trim()
you create a string.
Replace those two lines with just:
$myW3WP = $myW3WP.Sum / 1MB
And it'll work

Answer 2

$myW3WP is a string, not a number, so you're doing a textual comparison, rather than a numeric one. The line:
$myW3WP = ("{0:N2} " -f ($myW3WP.sum / 1mb))
Is what forces the variable to be a string. Just leave it as a number and don't worry about the decimal places:
$myW3WP = $myW3WP.sum / 1mb