Language: C C++ D Haskell Lua OCaml PHP Perl Plain Text Python Ruby Scheme Tcl <?php // sample code to illustrate the use of singleton design pattern // http://royads.blogspot.com class mysqlClass { protected static $_instance; public $username; function __construct() { } public static function getInstance() { if(null === self::$_instance) { self::$_instance = new mysqlClass(); } return self::$_instance; } } $singleDbConnection = mysqlClass::getInstance(); $singleDbConnection->username = 'user1'; $isItOtherDbConnection = mysqlClass::getInstance(); print $isItOtherDbConnection->username; // c the output of above line it prints the value which is set by the first object. Now this is what is singleton. ?> Private [?] Run code