Initialize class with only the name of the class as a string

I am attempting to use an already initialized class in a function with only the string name of the class being passed to said function.


class art{
  var $moduleInfo = "Hello World";

$art = new Art;


function getModuleInfo($moduleName){
    //I know I need something to happen right here.  I don't want to reinitialize the class since it has already been done.  I would just like to make it accessible within this function.
    echo $moduleName->moduleInfo;

Thanks for the help!