Check if value isset and null

Question

I need to check if value is defined as anything, including null. isset treats null values as undefined and returns false. Take the following as an

Answer 1

is_null($bar) returns true, since it has no values at all. Alternatively, you can use:

if(isset($bar) && is_null($bar)) // returns false

to check if $bar is defined and will only return true if:

$bar = null;
if(isset($bar) && is_null($bar)) // returns true