how to change date format in phpfrom mm/dd/yyyy to dd/mm/yyyy code example

Example 1: php date format dd/mm/yyyy

date("d/m/Y", strtotime($str));

Example 2: php convert date from dd/mm/yyyy to yyyy-mm-dd

$date = DateTime::createFromFormat('d/m/Y', "24/04/2012");
echo $date->format('Y-m-d');