<?php
class Bike
{
function __destruct()
{
  echo "½áÊøµÄʱºò»á¿´µ½Õâ¾ä»°";
}
}
$myBike = new Bike();
for($i=0;$i<5;$i++)
echo $i;
?>

<?php
class Bike
{
function __destruct()
{
  echo "½áÊøµÄʱºò»á¿´µ½Õâ¾ä»°";
}
}
$myBike = new Bike();
$myBike = null;
for($i=0;$i<5;$i++)
echo $i;
?>

<?php
class Bike
{
function __destruct()
{
  echo "½áÊøµÄʱºò»á¿´µ½Õâ¾ä»°";
}
}
$myBike = new Bike();
$youBike = $myBike;  //±äÁ¿youBikeÒ²Ö¸ÏòÁ˶ÔÏó
unset($myBike);  //ÕâÀﻹ²»»á³öÏÖ"½áÊøµÄʱºò»á¿´µ½Õâ¾ä»°",ÒòΪֻÊÇ»ØÊÕÁ˱äÁ¿$myBike
for($i=0;$i<5;$i++)
echo $i;
unset($youBike); 
//ÕâÀï¾Í»áÊä³öÁË£¬ÒòΪÔÚ»ØÊÕ$youBikeÕâ¸ö±äÁ¿µÄͬʱËùÓÐÖ¸ÏòBikeµÄ¶ÔÏó±äÁ¿¶¼Ã»ÁË
?>