Strugling with if, empty, and, or, - php

Question

The following script should create an error when date_enabled is 2 and one of the three variables is empty. When day is empty for example, the script still doesn't echo the sentence.
Does anybody sees the problem?
$year = $_POST['date-year'];
$month = $_POST['date-month'];
$day = $_POST['date-day'];
$date_enabled = 2;
if ((($date_enabled ==2)) && ((empty($year) || empty($day) || empty($month)))){
echo "You didn't enter a valid date";
}
UPDATE - When I perform the following script it echos: its empty its empty (function). Which means that empty and the function isEmpty, which I created because of the advice of #Expert System , also works.
if (empty($day)){
echo "its empty";
}
if (!isset($day)){
echo "its not set";
}
if (isEmpty($day)){
echo "its empty (function)";
}
UPDATE AGAIN - The script above works indeed correctly. The problem lays with my form. It works fine now and thanks for your help.

Answer 1

I believe the definition of "empty" in your question is unclear. If empty in your question means zero-length string, then empty function is not the right one for you.
empty() definition from PHP doucment
Determine whether a variable is considered to be empty. A variable is
considered empty if it does not exist or if its value equals FALSE.
empty() does not generate a warning if the variable does not exist.
Maybe this custom function will work in your context
function isEmpty($var) {
return !isset($var) || ($var == '');
}
Then
if (($date_enabled == 2) &&
(isEmpty($year) || isEmpty($day) || isEmpty($month))){
echo "You didn't enter a valid date";
}

Answer 2

Try this code instead:
$year = isSet($_POST["date-year"]) ? $_POST["date-year"] : "";
$month = isSet($_POST["date-month"]) ? $_POST["date-month"] : "";
$day = isSet($_POST["date-day"]) ? $_POST["date-day"] : "";
$date_enabled = 2;
if ((($date_enabled ==2)) && ((empty($year) || empty($day) || empty($month)))){
echo "You didn't enter a valid date";
}
The problem might be the error of level E_NOTICE raised when you try to access an undefined index in $_POST array.
This shoukd notcause a problem (i.e. stop execution) with theususl/default configuration options, but with yours it might (just guessing).