PHP单例模式
如何确保只制造一个对象
１：对象的产生，需要new或者clone
２：防止产生过多的对象，要防止new和clone／继承
３：综上，没有对象时，允许new，并把对象缓存．下次直接返回该对象
核心思想
<?php
final class sigle
{
/**
* @var null
*/
protected static $ins =null;
private function __construct()
{
}
private function __clone()
{
}
/**
* CreateDTime: 2021/6/16 14:35
* Function: ""
* @return sigle|null
*/
public static function getIns()
{
if (self::$ins==null){
self::$ins=new self();
}
return self::$ins;
}
}
$s1= sigle::getIns();
$s2= sigle::getIns();
if ($s1 === $s2){
echo '是一个对象';
}else{
echo '不是一个对象';
}
/*
new sigle();
class a extends sigle
{
}*/实例
<?php
class HttpService{
private static $instance;
public function GetInstance(){
if(self::$instance == NULL){
self::$instance = new HttpService();
}
return self::$instance;
}
public function Post(){
echo '发送Post请求', PHP_EOL;
}
public function Get(){
echo '发送Get请求', PHP_EOL;
}
}
$httpA = new HttpService();
$httpA->Post();
$httpA->Get();
$httpB = new HttpService();
$httpB->Post();
$httpB->Get();
var_dump($httpA == $httpB);