更改函数内的函数参数

HTML form sends empty values as empty strings. I want them to be null:

function dummy($arg1, $arg2, ... $argN)
{
   if(!$arg1) $arg1 = null;
   if(!$arg2) $arg2 = null;
   ... 
   if(!$argN) $argN = null

}

This is very ugly. I want something like:

function dummy($arg1, $arg2, ... $argN)
{
   nullEmptyArguments();
   var_dump($arg1); //null
}

Use function get_defined_vars() to get all defined variables, and loop over them and re-set them:

function dummy($arg1, $arg2, $argN)
{
    foreach (get_defined_vars() as $k => $v) $$k = $v ?: null;
    // your logic
}

dummy(1, '0', ''); # $arg2 & $argN will be set to NULL