Design mode-Singleton mode

1. What is a singleton mode

1. A class has only one instance object

2. This example is used throughout the system

2. Example

classtest{Static Private $_instance;  Public Static functiongetinstance () {if(Empty(Self::$_instance) ) { self::$_instance=Newtest (); }        returnSelf::$_instance; }     Public functionmy () {Echo' MyMy '; }}//$obj 1, $obj 2, $obj 3 equals$obj 1=test::getinstance ();$obj 2=test::getinstance ();$obj 3=test::getinstance ();//Output MyMyEcho $obj 3->my ();

A singleton can reduce the cost of creating objects and reduce system expenses.

Design mode-Singleton mode