PHP入门-使用面向对象思想开发的图形计算器

Bertha 。 2022-06-03 01:21 133阅读 0赞

本文使用面向对象的思想，做了一个图形计算器的小例子：

1、架构图

![20171218223233610][]

2、说明

（1）index.php页面只需要直接调用Form类和Result类

（2）Form类用于输入一个表单

（3）为了实现多态的特性，Result类用于操作数据

3、Shape类

<?php
        abstract class Shape{
            abstract function area();//面积
            abstract function perimeter();//周长
        }

4、Rectangle类

<?php
        class Rectangle extends Shape {
            private $width=0;
            private $height=0;
    
            function __construct($width,$height){
                $this->width=$width;
                $this->height=$height;
            }
    
            function area(){
                return $this->width * $this->height;
            }
    
            function perimeter(){
                return 2*$this->width + 2*$this->height;
            }
    }

5、Triangle类

<?php
        class Triangle extends Shape {
            private $side1=0;
            private $side2=0;
            private $side3=0;
    
            function __construct($side1,$side2,$side3){
                $this->side1=$side1;
                $this->side2=$side2;
                $this->side3=$side3;
            }
    
            function area(){
                if ($this->isTriangle()){
                    $temp=($this->side1 + $this->side2 + $this->side3)/2;
                    return sqrt($temp * ($temp - $this->side1) * ($temp - $this->side2) * ($temp - $this->side3) );
                }else{
                    return "无法构成三角形";
                }
            }
    
            function perimeter(){
                if ($this->isTriangle()){
                    return $this->side1 + $this->side2 + $this->side3;
                }else{
                    return "无法构成三角形";
                }
            }
    
            //需要验证是否能构成三角形
            function isTriangle(){
                if (($this->side1 + $this->side2 > $this->side3)&&($this->side1 + $this->side3 > $this->side2)&&($this->side2 + $this->side3 > $this->side1)){
                    return true;
                }else{
                    return false;
                }
            }
    }

6、Circle类

<?php
        class Circle extends Shape {
            private $radius=0;
    
            function __construct($radius){
                $this->radius=$radius;
            }
    
            function area(){
                return M_PI * $this->radius * $this->radius;
            }
    
            function perimeter(){
                return 2 *  M_PI * $this->radius;
            }
    }

7、Result类

<?php
        class Result{
            private $shape=null;//形状
            private $result='';//结果
    
            //通过不同的名字，创建不同的对象
            function __construct(){
                switch ($_POST["subForm"]){
                    case "rectangle":
                        $this->shape=new Rectangle($_POST["width"],$_POST["height"]);
                        break;
                    case "triangle":
                        $this->shape=new Triangle($_POST["side1"],$_POST["side2"],$_POST["side3"]);
                        break;
                    case "circle":
                        $this->shape=new Circle($_POST["radius"]);
                        break;
                    default:
                        $this->shape=new Rectangle($_POST["width"],$_POST["height"]);
                }
            }
            function __toString(){
                $this->result.='面积是：'.$this->shape->area();
                $this->result.='周长是：'.$this->shape->perimeter();
                return $this->result;
            }
        }

8、Form类

<?php
        class Form{
            private $index;//位置
    
            function __construct($index="index.php"){
                $this->index=$index;
            }
    
            function __toString(){
                $form='<form action="'.$this->index  .'?action='. $_GET["action"]  .'" method="post">';
                switch ($_GET["action"]){
                    case "rectangle":
                        $form.=$this->getRectangle();
                        break;
                    case "triangle":
                        $form.=$this->getTriangle();
                        break;
                    case "circle":
                        $form.=$this->getCircle();
                        break;
                    default:
                        $form.=$this->getRectangle();
                }
                $form.='<input type="text" hidden="hidden" name="subForm" value="'.$_GET["action"].'">';
                $form.='<input type="submit" value="计算">';
                $form.='</form>';
                return $form;
            }
    
            function getRectangle(){
                $rectangle='矩形:<br>';
                $rectangle.='宽度：<input type="text" name="width">'.'<br>';
                $rectangle.='高度：<input type="text" name="height">'.'<br>';
                return $rectangle;
            }
            function getTriangle(){
                $rectangle='三角形:<br>';
                $rectangle.='边一：<input type="text" name="side1">'.'<br>';
                $rectangle.='边二：<input type="text" name="side2">'.'<br>';
                $rectangle.='边三：<input type="text" name="side3">'.'<br>';
                return $rectangle;
            }
            function getCircle(){
                $rectangle='圆形:<br>';
                $rectangle.='半径：<input type="text" name="radius">'.'<br>';
                return $rectangle;
            }
        }

9、index.php

<html lang="cn">
    <head>
        <meta charset="UTF-8">
        <title>图形计算</title>
    </head>
    <body>
        <center>
            <h1>计算图形</h1>
            <a href="index.php?action=rectangle">矩形</a>
            <a href="index.php?action=triangle">三角形</a>
            <a href="index.php?action=circle">圆形</a>
        </center>
    
        <?php
    //        error_reporting(E_ERROR);
    //        ini_set("display_errors","Off");  //屏蔽掉PHP警告和错误提示
    
            //类的自动加载
            function __autoload($className){
                include strtolower($className).".class.php";
            }
    
            //显示表单
            echo new Form();
            echo '<br><br><br><br>结果：<br>';
            //操作数据
            echo new Result();
        ?>
    </body>
    </html>

[20171218223233610]: /images/20220603/17b12631cf6b45afabcc7e51d3785190.png