Description:
------------
if (empty($var)){
   ...
}

this has an impression that we are trying freeing up $var and making it 'NULL'
it sound like 'DoEmpty()' or 'SetEmpty()'

but what this function realy is: 
isEmpty()

the script should looks like this:
if(isempty($var)){
   ...
}
because IMHO 'do','set' and 'let' are optional prefixes, which let you understand that this function is an order (a command)
but not the prefix 'is' which is if we can say a test prefix.