Check a year whether it is leap year or not

 <?php

$year = 2019;

if ($year % 400 == 0) {

   echo $year." is a leap year.";

} elseif ($year % 100 == 0) {

   echo $year." is not a leap year.";

} elseif ($year % 4 == 0) {

   echo $year." is a leap year.";

} else {

   echo $year." is not a leap year.";

}

?>