Get Instance of class SingletonDemo into variable $foo
$foo = SingletonDemo::getInstance();
$foo->getVar() :: Expecting result => NULL
NULL
Set SingletonDemo to "buz"
$foo->setVar("buz")
$foo->getVar() :: Expecting result => string(3) "buz"
string(3) "buz"
Get Instance of class SingletonDemo into variable $foo
$bar = SingletonDemo::getInstance();
$bar->getVar() :: Expecting result => string(3) "buz"
string(3) "buz"
$foo->setVar("qar")
$foo->setVar("qar");
$bar->getVar() :: Expecting result => string(3) "qar"
string(3) "qar"
$foo->getVar() :: Expecting result => string(3) "qar"
string(3) "qar"
$bar->setVar("that's it")
$bar->setVar("that's it");
$bar->getVar() :: Expecting result => string(9) "that's it"
string(9) "that's it"
$foo->getVar() :: Expecting result => string(9) "that's it"
string(9) "that's it"