Collection
Collection
/**
* 单例模式
* 1.类只允许被实例化一次;
* 2.类中只提供私有构造函数；
* 3.类中含有一个静态私有的对象；
* 4.类中提供一个公有静态方法供类，用于类创建本身的静态私有对象；
*/
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
<?php
class config{
//创建私有对象
private static $instance = null;
//参数容器
private $config;
public $setting = [];
//私有构造方法 禁止从类的外部实例化类
private function __construct()
{
}
//禁止克隆类
private function __clone()
{
// TODO: Implement __clone() method.
}
//公有静态方法
public static function getInstance()
{
if(self::$instance == null)
{
self::$instance = new self();
}
return self::$instance;
}
public function set()
{
$num = func_num_args();//返回函数参数的个数
if($num>0)
{
switch ($num)
{
case 1:
$value = func_get_arg(0);
if(is_array($value))
{
$this->setting = array_merge($this->setting,$value);
}
break;
case 2:
$name = func_get_arg(0);//参数健
$value = func_get_arg(1);//参数值
$this->setting[$name] = $value;
break;
default;
}
}else{
echo '<span>没有传入参数</span>';
}
}
function get($name='')
{
if(empty($name))
{
return $this->setting;
}
return $this->setting[$name];
}
}
$cfg = config::getInstance();
//$cfg -> set('host','localhost');
//echo $cfg->get('host');
$config = [
'host'=>'localhost',
'user'=>'root',
'pwd'=>'root'
];
$cfg -> set($config);
echo '<pre>';
var_dump($cfg->get());点击 "运行实例" 按钮查看在线实例
mvc模式
//模型层 Model
<?php
//模型类
namespace mvc\model;
class Model
{
public $pdo = null;
//连接数据库
public $result = [];
public function __construct($dbname, $user, $pass)
{
$this->pdo = new \PDO('mysql:host=127.0.0.1;dbname='.$dbname, $user, $pass);
}
//查询
public function select($table, $num)
{
//创建预处理对象
$stmt = $this->pdo->prepare("SELECT `id`,`name`,`age`,`salary` FROM {$table} LIMIT :num");
//执行查询
$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
／/视图层View
<?php
/*
* 视图类
*/
namespace mvc\view;
class View
{
public $data = [];
function __construct($data)
{
$this->data = $data;
}
function getdata()
{
return $this->data;
}
function display($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>Document</title>
</head>
<body>';
$table.='<table border="1" cellspacing="0" cellpadding="0" width="400" align="center"><tr style="background: #eb7350;color: #FFF"><th>ID</th><th>姓名</th><th>地址</th></tr>';
foreach ($data as $stu)
{
$table .='<tr align="center"><td>'.$stu['id'].'</td><td>'.$stu['name'].'</td><td>'.$stu['address'].'</td></tr>';
}
$table.='</table>
</body>
</html>';
echo $table;
}
}点击 "运行实例" 按钮查看在线实例
//控制层 Controller
<?php
/**
* 控制层
*/
namespace mvc\controller;
use mvc\model\Model;
use mvc\view\View;
class Controller
{
function index()
{
require './mvc/model/Model.php';
$model = new Model('mysql:host=localhost;dbname=data','root','root');
$result = $model->select('stu',5);
require'./mvc/view/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
／/框架入口文件
<?php /** * 框架入口文件 */ require './mvc/controller/Controller.php'; use mvc\controller\Controller; $index= new Controller(); $index->index();
点击 "运行实例" 按钮查看在线实例
* mvc模式的设计思想：
* M：model封装了数据库的链接和数据的处理操作；
* V：view封装了对数据model层的展示效果；
* C：contrller model层和view层的调度者；
