PHP関数リファレンス

function &referenceFunc() {    static $foo = '';    return $foo;        }//将静态变量$foo的引用传递给$name$bar = &referenceFunc();$bar .= "hello";//作为普通函数调用echo referenceFunc();//删掉引用unset($bar);//作为普通函数调用$bar = referenceFunc();$bar .= " world";//$foo并不会发生变化echo referenceFunc();

class Reference {    private $foo;    public function &referenceFoo() {        return $this->foo;    }        public function getFoo() {        echo $this->foo . "<br>";    }}$obj = new Reference();//将私有变量绑定在了一个普通变量$bar上$bar = &$obj->referenceFoo();//外部操作私有变量$bar .= "access the private var in outside";//输出'access the private var in outside'$obj->getFoo();