تابع ‎empty()‎‎ در PHP

<?php
$a = 0;

// True because $a is empty
if (empty($a)) {
  echo  "Variable 'a' is empty.<br>";
}

// True because $a is set
if (isset($a))  {
  echo "Variable 'a' is set";
}
?>
<?php
$a = 0;

// True because $a is empty
if (empty($a)) {
  echo  "Variable 'a' is empty.<br>";
}

// True because $a is set
if (isset($a))  {
  echo "Variable 'a' is set";
}
?>اجرای کد