FlyWeight.class.php

<?php
interface Flyweight{
    public function operation();
}

class MyFlyweight implements Flyweight
{
    protected $intrinsicState;
    function __construct($str)
    {
        $this->intrinsicState = $str;
    }

    public function operation()
    {
        echo 'MyFlyweight['.$this->intrinsicState.'] do operation. <br>';
    }
}

class FlyweightFactory
{
    protected static $flyweightPool;
    function __construct()
    {
        if (!isset(self::$flyweightPool)) {
            self::$flyweightPool = [];
        }
    }
    public function getFlyweight($str)
    {

        if (!array_key_exists($str,self::$flyweightPool)) {
            $fw = new MyFlyweight($str);
            self::$flyweightPool[$str] = $fw;
            return $fw;
        } else {
            echo "aready in the pool,use the exist one: <br>";
            return self::$flyweightPool[$str];
        }

    }
}