class yunsuan
{
public $a;
public $b;
function suan()
{
echo "对两个数进行运算";
}
}
class jia extends yunsuan
{
function suan()
{
return $this->a+$this->b;
}
}
class jian extends yunsuan
{
function suan()
{
return $this->a-$this->b;
}
}
class cheng extends yunsuan
{
function suan()
{
return $this->a*$this->b;
}
}
class chu extends yunsuan
{
function suan()
{
return $this->a/$this->b;
}
}
//对扩展开放,对修改封闭
//工厂类
class gongchang
{
//给一个参数,返回一个对象
static function chanpin($name)
{
switch ($name)
{
case"+":
return new jia();
break;
case"-":
return new jian();
break;
case"*":
return new cheng();
break;
case"/":
return new chu();
break;
}
}
}
//$a=gongchang::chanpin("+");
//var_dump($a);
//$a=gongchang::chanpin("-");
//var_dump($a);
//$a=gongchang::chanpin("*");
//var_dump($a);
$a=gongchang::chanpin("/");
var_dump($a);