Powershell Replace variable with operator

Question

Hi.
I have just started using powershell. I google and search the help from powershell, but just don't seem to find what I am looking for.

Don't know how to go about this.

lets say I have this code:

$a = "-eq"
$b = "-lt"
$c = "-gt"

$op = $a

if (3 $op 3) {  #<=== How do I convert this so it see's -eq and does the operation??
    write-host "equal"

}

How can I use $op so it does the operation?
I need to convert it from string to operator?
Do I have to set the variable as something else than a string.

Thank you.

Answer 1

 $a = "-eq"
 $b = "-lt"
 $c = "-gt"

 $op = $a

 if ((Invoke-expression "3 $op 3")) {  #<=== How do I convert this so it see's -eq and does the operation??
     write-host "equal"      
 }