How to write if else in one line in shell?

I would like to write in one line this:

if [$SERVICESTATEID$ -eq 2]; then echo "CRITICAL"; else echo "OK"; fi

So to do a test in my shell I did:

if [2 -eq 3]; then echo "CRITICAL"; else echo "OK"; fi

The result is

-bash: [2: command not found
OK

So it doesn't work.