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.

Example:


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

$art = new Art;

getModuleInfo("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!