return $this->cdInfo[$song] . '.mp3';
}
public function playMp4($song)
{
return $this->cdInfo[$song] . '.mp4';
}
}
$oldCd = new cd();
$oldCd->addSong("1");
$oldCd->addSong("2");
$oldCd->addSong("3");
$type = 'mp3';
if ($type == 'mp3') {
echo $oldCd->playMp3(1);
} else {
echo $oldCd->playMp4(2);
}
//委托模式-去除核心对象中的判决和复杂的功能性
//改进cd类
class cdDelegate
{
protected $cdInfo = array();
public function addSong($song)
{
$this->cdInfo[$song] = $song;
}
public function play($type, $song)
{
$obj = new $type();
return $obj->playList($this->cdInfo, $song);
}
