简易图形计算器
矩形 | 三角形| 圆形
view($_POST); if (isset($_POST['sub'])) { echo "
"; if ($shape->yan($_POST)) { echo "".$shape->name."的周长".$shape->zhou().""."
"; echo "
"; echo "".$shape->name."的面积".$shape->area().""."
"; }else { echo "错误：$shape->error"; } echo "
"; } } else { echo "请选择一个图形"; } ?>

width = $arr['width']; $this->height = $arr['height']; } $this->name = "矩形"; $this->error = ''; } function area() { return $this->width * $this->height; } function zhou() { return ($this->width+$this->height) * 2; } function view($arr) { $form .= "
"; $form .= "请输入".$arr['name']."的宽度：
"; $form .= "
"; $form .= "请输入".$arr['name']."的长度：
"; $form .= "
"; $form .= " "; $form .= ""; $form .= "
"; echo $form; } function yan($arr) { $bz = true; if ($arr['width']< 0) { $this->error .= "宽度小于0；"; $bz = false; } else { if (!is_numeric($arr['width'])) { $this->error .= "宽不是数字；"; $bz = false; } } if ($arr['height']< 0) { $this->error .= "宽度小于0；"; $bz = false; } else { if (!is_numeric($arr['height'])) { $this->error .= "高不是数字；"; $bz = false; } } return $bz; } } ?>

bian1 = $arr['bian1']; $this->bian2 = $arr['bian2']; $this->bian3 = $arr['bian3']; } $this->name = "三角形"; $this->error = ''; } function area() { $p = ($this->bian1 + $this->bian2 + $this->bian3) / 2; // p(p-a)(p-b)(p-c) return sqrt($p*($p-$this->bian1)*($p-$this->bian2)*($p-$this->bian3)); } function zhou() { return $this->bian1+$this->bian2+$this->bian3; } function view($arr) { $form .= "
"; $form .= "请输入".$arr['name']."的第一条边：
"; $form .= "
"; $form .= "请输入".$arr['name']."的第二条边：
"; $form .= "
"; $form .= "请输入".$arr['name']."的第三条边：
"; $form .= "
"; $form .= " "; $form .= ""; $form .= "
"; echo $form; } function yan($arr) { $bz = true; if ($arr['bian1']< 0) { $this->error .= "第一条边小于0；"; $bz = false; } else { if (!is_numeric($arr['bian1'])) { $this->error .= "第一条边不是数字；"; $bz = false; } } if ($arr['bian2']< 0) { $this->error .= "第二条边小0；"; $bz = false; } else { if (!is_numeric($arr['bian2'])) { $this->error .= "第二条边不是数字；"; $bz = false; } } if ($arr['bian2']< 0) { $this->error .= "第三条边小于0；"; $bz = false; } else { if (!is_numeric($arr['bian2'])) { $this->error .= "第三条边不是数字；"; $bz = false; } } if (($this->bian1+$this->bian2) < $this->bian3 ||($this->bian1+$this->bian3) < $this->bian2 ||($this->bian2+$this->bian3) < $this->bian1) { $this->error .= "三条边不能构成三角形"; $bz = false; } return $bz; } } ?>