Strategy.php

<?php
/**
 * Created by PhpStorm.
 * User: haobin
 * Date: 2017/10/9
 * Time: 23:23
 */

/**
 *
 * 策略模式
 */
interface IStrategy{
    function filter($record);
}

class FindAfterStrategy implements IStrategy{
    private $_name;

    public function __construct($name)
    {
        $this->_name = $name;
    }

    public function filter($record)
    {
        return strcmp($this->_name, $record) <= 0;
    }
}

class RandomStrategy implements IStrategy{
    public function filter($record)
    {
        return rand(0, 1) < 0.5;
    }
}

class UserList{
    private $_list = array();

    public function __construct($names)
    {
        if($names != null){
            foreach($names as $name){
                $this->_list [] = $name;
            }
        }
    }

    public function add($name)
    {
        $this->_list [] = $name;
    }

    public function find($filter)
    {
        $recs = array();
        foreach($this->_list as $user){
            if($filter->filter($user))
                $recs [] = $user;
        }
        return $recs;
    }
}

$ul = new UserList(array("Andy", "Jack", "Lori", "Megan"));
$f1 = $ul->find(new FindAfterStrategy("J"));
print_r($f1);

$f2 = $ul->find(new RandomStrategy());
print_r($f2);