class Strategy2 implements IStrategy
{
function Move(Context $context) : int
{
$context->counter -= 1;
return $context->counter;
}
}
class Context
{
private $strategy;
public $counter = 0;
public function setStrategy(IStrategy $strategy)
{
$this->strategy = $strategy;
}
public function Algorithm() : int
{
return $this->strategy->Move($this);
}
}
$context = new Context();
$strategy1 = new Strategy1();
$strategy2 = new Strategy2();
$context->setStrategy($strategy1);
for ($i = 0; $i < 30; $i++) {
if ($i == 15) {
$context->setStrategy($strategy2);
}
echo "Counter = ", $context->Algorithm(), "\n";
}
<?php /** * Created by PhpStorm. * User: gary * Date: 7/31/16 * Time: 2:53 PM */ namespace DPHP\Strategy; require_once __DIR__ . '/../autoload.php'; $ctx = new Context(); // 打折 echo '===============打xx折===============', PHP_EOL; $ctx->setStrategy(new Discount()); $price = $ctx->cal(300); echo $price, PHP_EOL; // 满xx减免yy echo '===============满xx减免yy===============', PHP_EOL; $ctx->setStrategy(new Reduce()); $price = $ctx->cal(300); echo $price, PHP_EOL; // xx以上打yy折 echo '===============xx以上打yy折===============', PHP_EOL; $ctx->setStrategy(new Promotional()); $price = $ctx->cal(300); echo $price, PHP_EOL;
private $strategy = null;
//用于保存策略
/**
* 设置指定的策略
* @param Strategy $strategy
*/
public function setStrategy(Strategy $strategy)
{
$this->strategy = $strategy;
}
/**
* 执行策略的方法
*/
public function index()
{
if (empty($this->strategy)) {
echo 'no stragety';
exit;
}
//执行策略的方法
$this->strategy->algorithmInterface();
}
}
//usage:
$context = new Context();
$strategyA = new StrategyA();
//实例化策略A
$context->setStrategy();
//设置策略A
$context->index();
//执行策略
