同样问一个关于class的有趣现象~~

环境：PHP 5.0.2<?php
$test2=1024;
class T2{
function T2(){
global $test2;
echo $test2;
}
}
$t2=new T2;
$t2;//输出1024
echo "<br>\n";
echo "================================<br>\n";
$test3=11;
class T3{
function T3(){
global $test3;
$test3 = &$test3;
echo $test3;
}
}
$t3=new T3;
$t3;//输出11?>