PHP Single-instance mode

A singleton mode is typically used on a database connection

Specific code examples:

<?PHPclass Mysql {    Private $conn; Private Static $instance=NULL; Private function__construct () {$conn= @mysql_connect(' localhost ', ' root ', ' root '); }    //single-case mode     Public  Static functiongetinstance () {if(! Self::$instanceinstanceof Self) { Self::$instance=NewSelf ; }        returnSelf::$instance; }     //Prevent cloning    Private function__clone () {}}$mysql=Mysql::getinstance ();$mysql 2=Mysql::getinstance ();Var_dump($mysql);Echo' ;Var_dump($mysql 2);

PHP Single-instance mode