//面向对象求面积
class Yuan
{
//存储半径的变量
var $banjing;
//求面积的方法
function MianJi()
{
return 3.14*$this->banjing*$this->banjing;
}
}
//求面积
$r1 = new Yuan();
$r1->banjing = 10;
$dmj = $r1->MianJi();
$r2 = new Yuan();
$r2->banjing=5;
$xmj = $r2->MianJi();
echo $dmj-$xmj;
