equality operator in powershell

Hello

I'd like to know what's wrong with the following script

if ($fileloc.Length = 0) { … }
if ($logloc.Length = 0) { … }

it gives me that "Length" is a ReadOnly property. I tried the following but no success

if ($fileloc.Length == 0) { … }
if ($logloc.Length == 0) { … }