Simple (?) var_dump question

Hi. I'm new to the list so sorry if this has already been asked before .... I want to find a way to capture the var_dump output as a string so I can write it to a log file ... (for example): $logger->debug(var_dump($foo)); So, the above line would get a "var_dump stringified" version of $foo and pass it to my logger's debug method. Thanks in advance for any help. Tom.