PHP怎样编写一个图形计算器？-群英

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PHP如何编写图形计算器？对四则运算计算器我们都很熟悉了，有些朋友就好奇能不能对图像计算呢？当然是可以的，下面就给大家介绍一下如何实现三角形，矩形和圆形计算的简易计算器。

主函数：index.php

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>图形计算器</title>
<style>
 * {
 margin: 0px;
 padding: 0px;
 }
 #contains {
  width: 500px;
 margin: 20px auto;
 background: #0C0;
 text-align: center;
 
 }
 h1 {
  width: 500px;
 height: 60px;
 }
 a {
  font-size: 20px;
 text-decoration: none;
 }
 
 #footer {
  width: 300px;
 background: #fff;
 margin: 0 auto;
 padding: 5px 10px;
 border-radius: 150px;
 }
</style>
</head>
 
<body>
 <div id="contains">
  <h1>简易图形计算器</h1>
 <a href='index.php?action=rect'>矩形</a> |
 <a href='index.php?action=triangle'>三角形</a>|
 <a href='index.php?action=cirle'>圆形</a> 
 <hr>
 
 <?php
  ini_set("display_errors", "On"); //开启错误调试
 //设置错误报告的级别，除了无关紧要的'注意'，其他的报告都输出
 error_reporting(E_ALL & ~E_NOTICE);
 
 function __autoload($classname) { //魔术方法 自动加载类
  include strtolower($classname).".class.php"; //将类名转化成小写
 }
 // include "shape.class.php";
 // include "rect.class.php";
  if (!empty($_GET['action'])) {
 // echo "传送成功";
  $classname = ucfirst($_GET['action']);
  $shape = new $classname($_POST);
  $shape->view($_POST);
 
  if (isset($_POST['sub'])) {
  echo "<div id='footer'>";
  if ($shape->yan($_POST)) {
   
   echo "<b>".$shape->name."的周长".$shape->zhou()."</b>"."<br>";
   echo "<br>";
   echo "<b>".$shape->name."的面积".$shape->area()."</b>"."<br>";
  }else {
   echo "<b>错误：$shape->error</b>";
  }
  echo "</div>";
  }
  
 } else {
  echo "请选择一个图形";
 }
 
 ?>
 
 </div>
</body>
</html>

先定义一个抽象类

<?php 
 abstract class Shape {
 private $name;
 private $error;
 abstract function area();
 abstract function zhou();
 abstract function view($arr);
 abstract function yan($arr);
 }
?>

矩形类的编写

<?php
 class Rect extends Shape {
 private $width;
 private $height;
 
 function __construct($arr = array()) {
  if (!empty($arr)) {
   $this->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 action='index.php?action=rect' method='post'>";
  $form .= "请输入".$arr['name']."的宽度：<input type='text' name='width' value='".$_POST['width']."'/><br>";
  $form .= "<br>";
  $form .= "请输入".$arr['name']."的长度：<input type='text' name='height' value='".$_POST['height']."'/><br>";
  $form .= "<br>";
  $form .= "<input type='submit' name='sub' value='提交'/>  ";
  $form .= "<input type='reset' name='ret' value='重置'/>";
  $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;
 }
 }
?>

三角形类：

<?php
 class Triangle extends Shape {
  private $bian1;
 private $bian2;
 private $bian3;
  
 function __construct($arr = array()) {
  if (!empty($arr)) {
   $this->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 action='index.php?action=triangle' method='post'>";
  $form .= "请输入".$arr['name']."的第一条边：<input type='text' name='bian1' value='".$_POST['bian1']."'/><br>";
  $form .= "<br>";
  $form .= "请输入".$arr['name']."的第二条边：<input type='text' name='bian2' value='".$_POST['bian2']."'/><br>";
  $form .= "<br>";
  $form .= "请输入".$arr['name']."的第三条边：<input type='text' name='bian3' value='".$_POST['bian3']."'/><br>";
  $form .= "<br>";
  $form .= "<input type='submit' name='sub' value='提交'/>  ";
  $form .= "<input type='reset' name='ret' value='重置'/>";
  $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;
 }
 }
?>

其他的类只要按照上面的格式改下就很好写出来了。