class Keyboard{
    public function run() {
        return '我能打字';
    }
}
class Mouse {
    public function run() {
        return '我能控制光標(biāo)';
    }
}
class Factory {
    public static function build($key) {
        if($key == 'mouse') {
            return new Mouse();
        } else if ($key == 'keyboard') {
            return new Keyboard();
        }
    }
}
//----------調(diào)用端----------
$res = Factory::build('mouse')->run();
/*
筆者認(rèn)為，簡(jiǎn)單工廠可以簡(jiǎn)化為以下寫法
但是這會(huì)有三個(gè)缺陷：
1. 能否做到類名寫法一致？不一定能做到
2. 缺少白名單機(jī)制，不安全，指不定new那個(gè)類，特別是這個(gè)參數(shù)守用戶傳參影響的場(chǎng)景，不過(guò)這個(gè)可以讓需要實(shí)例化的類實(shí)現(xiàn)一個(gè)接口，工廠方法添加typehint （類型約束）限制。
3. 如果修改白名單，又違背了開閉原則。
*/
class Factory {
    public static function build($class) {
        return ucfirst($class);
    }
}

interface Usb {
    public function run();
}
class Keyboard implements USb {
    public function run() {
        return '我能打字';
    }
}
class Mouse implements USb {
    public function run() {
        return '我能控制光標(biāo)';
    }
}
interFace Factory {
    public static function build();
}
class KeyboardFactory implements Factory {
    public static function build() :Keyboard {
        return new Keyboard();
    }
}
class MouseFactory implements Factory {
    public static function build() :Mouse {
        return new Mouse();
    }
}
//----------調(diào)用端----------
$res = MouseFactory::build()->run();

interface Talk {
    public function say();
}
class EnglishTalk implements Talk {
    public function say() {
        return 'I can speak English';
    }
}
class ChineseTalk implements Talk {
    public function say() {
        return '我會(huì)說(shuō)中文';
    }
}
interface Write {
    public function writeWord();
}
class EnglishWrite implements Write {
    public function writeWord() {
        return 'I can write English words';
    }
}
class ChineseWrite implements Write {
    public function writeWord() {
        return '我會(huì)寫漢字';
    }
}
interface Factory {
    public static function buildSay();
    public static function buildWriteWord();
}
class EnglishFactory implements Factory {
    public static function buildSay() :EnglishTalk {
        return new EnglishTalk();
    }
    public static function buildWriteWord() :EnglishWrite {
        return new EnglishWrite();
    }
}
class ChineseFactory implements Factory {
    public static function buildSay() :ChineseTalk {
        return new ChineseTalk();
    }
    public static function buildWriteWord():ChineseWrite {
        return new ChineseWrite();
    }
}
//----------調(diào)用端----------
//中國(guó)人對(duì)應(yīng)會(huì)說(shuō)漢語(yǔ)，或?qū)憹h字，這就是有關(guān)聯(lián)，
$chinese_say        = ChineseFactory::buildSay()->say();
$chinese_write_word = ChineseFactory::buildWriteWord()->writeWord();