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Correction status：qualified
Teacher's comments：
Collection
Collection
1.编程: 单例模式:
<?php
//1.编程: 单例模式
echo '//1.编程: 单例模式','<hr>';
class Student {
//private $name;
//private $age;
private static $instance = null;
//private 外部就没办法实例化了
private function __construct()
{
//$this->name = $name;
//$this->age = $age;
}
//克隆方法私有化,外部也就无法访问了
private function __clone()
{
// TODO: Implement __clone() method.
}
//外部仅通过公共的静态方法创建实例
public static function getInstance()
{
//检测当前类的属性是否已经保存了当前类的实例
if (self::$instance == null)
{
self::$instance == new self();
}
//返回当前的实例
return self::$instance;
}
}
$obj1 = Student::getInstance();
$obj2 = Student::getInstance();
var_dump($obj1,$obj2);
echo '<br>';
var_dump($obj1 === $obj2);
echo '<br><br>';点击 "运行实例" 按钮查看在线实例
2.编程: MVC的实现原理:
Model:
<?php
class Model
{
private $pdo = null;
public $result = [];
//连接数据库
public function __construct($dbname,$user,$pass)
{
$this->pdo = new \PDO('mysql:host=127.0.0.1;dbname='.$dbname,$user,$pass);
}
//查询
public function select($table,$num)
{
$stmt = $this->pdo->prepare("SELECT `id`,`name`,`age` FROM {$table} LIMIT :num");
//执行查询 查询10条信息 value:$num
$stmt->bindValue(':num',$num,PDO::PARAM_INT);
$stmt->execute();
$this->result = $stmt->fetchAll(PDO::FETCH_ASSOC);
}
}点击 "运行实例" 按钮查看在线实例
View:
<?php
/**
* Created by PhpStorm.
* User: T3rdW
* Date: 2018/9/8
* Time: 14:26:34
*/
class View
{
public $data = [];
public function __construct($data)
{
$this->data = $data;
}
public function getData()
{
return $this->data;
}
public function display($data)
{
$table = '
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>MVC模式</title>
<style>
table,th,td{
border: 1px solid black;
}
table {
border-collapse: collapse;
width: 600px;
margin: 30px auto;
text-align: center;
}
table tr:first-child {
background-color: #39FF1B;
}
table caption {
font-size: 1.5em;
margin-bottom: 15px;
}
</style>
<table>
<caption>员工信息表</caption>
<tr>
<th>ID</th>
<th>姓名</th>
<th>年龄</th>
</tr>';
foreach ($data as $user)
{
$table .= '<tr>';
$table .= '<td>'.$user['id'].'</td>';
$table .= '<td>'.$user['name'].'</td>';
$table .= '<td>'.$user['age'].'</td>';
$table .= '</tr>';
}
$table .= '</table></body></html>';
echo $table;
}
}点击 "运行实例" 按钮查看在线实例
Controller:
<?php
/**
* Created by PhpStorm.
* User: T3rdW
* Date: 2018/9/8
* Time: 14:44:59
*/
class Controller
{
public function index($num)
{
require 'Model.php';
$model = new Model('user','root','root');
$model->select('name',$num);
$result = $model->result;
require 'View.php';
$view = new View($result);
$data = $view->getData();
$view->display($data);
}
}点击 "运行实例" 按钮查看在线实例
