对象依赖、成员变量（作业示例）

Question

我正在创建一个羊毛农场，如果羊老了，他们会在机器里剪毛。羊毛是按颜色来计算的，有黑有白的。

每个提到的属性都是随机的：

• 年龄：年轻 = 0，老 = 1
• 颜色（黑色、白色）。

逻辑我明白了，但是我不知道怎么把羊群发到机器上，而且如果我多做羊，我不能让计数器增加。 （在分配过程中，我被要求这样做）。

我对代码进行了注释以进一步理解： http://gabrielmeono.com/theFarm.zip

<?php 
class Sheep{
    //Atributes
    const COLOR_WHITE = 'white';
    const COLOR_BLACK = 'black';
    const AGE_YOUNG = 0;
    const AGE_OLD = 1;

    private $_color;
    private $_age;

    //Random age and color
    public static function makeRandom(){
    if(rand(0, 1)){
        $color = self::COLOR_WHITE;
    }else{
        $color = self::COLOR_BLACK;
    }
        $age = rand(0, 1);
        return new self($color, $age);
    }

    public function __construct($color, $age){
        $this->_color = $color;
        $this->_age = $age;
    }
    //To check if the sheep was created and had all the atributes.
    public function report(){
        echo '<br>This sheep is '.$this->_color.' and '.$this->_age.'<br/>';//Old age is 1. 

        }

}


class machine {
    //The machine should shear wool only if the sheep is old. Old equals 1.
    public function Shear($collector){
        switch($collector)
        {
            case $sheep->_age = 1;
                echo 'Sheep sheared <br/>';
            break;
            default:
                echo 'This sheep is not ready to be sheared <br/>';
            break;

        }
    }
    //Here I should be able to count and separate wool by color.
    public function Counter($whiteWool, $blackWool, $count){ //This is my notion how it should start...Correct me if I'm wrong.


        }
    }

$sheep = Sheep::makeRandom();
$sheep -> report();
$machine = new machine ();
$machine -> Shear(0);
//I don't know how to connect the machine class with the sheep class.
//Batch creation and processing of sheep is beyond my understanding.
?>

Answer 1

正如其他人所说，您可以通过注射将羊添加到机器中。 shear 方法实际上对我来说最有意义。

public function Shear(Sheep $sheep) {
   switch ($sheep->age) {} // etc.
}

事实上，我会更进一步，让绵羊对剪毛做出反应。

public static function makeRandom() {
   // ...
   return new $age ? OldSheep($color) : YoungSheep($color);
}

甚至更好：

private static $ages = array(0 => 'Old', 1 => 'Young')
public static function makeRandom() {
   // ...
   $sheepclass = $ages[$age] . 'Sheep';
   return new $sheepclass($color);
}

那么到了剪羊毛的时候：

interface Sheepable {
   function prepareToShear(machine $mach);
}

class OldSheep implements Sheepable {
   public function prepareToShear(machine $mach) {
      echo "Sheep is ready to be shorn";
      $mach->shear($this);
   }
}

class YoungSheep implements Sheepable {
   public function prepareToShear(machine $mach) {
      echo "Sheep is not ready to be shorn";
   }
}

class machine {
   //... etc.
   public function Shear(Sheepable $sheep) {
      $sheep->prepareToShear($this);
   }
}

顺便说一句，在这里寻求家庭作业的帮助往往会得到负面的回应。

Answer 2

您可以使用依赖注入将Sheep 对象注入Machine（todo: google for it）。

例如

$machine->addSheep($sheep);

addSheep 方法应该将$sheep 对象保存在类成员变量中。以后其他方法可能会用到这个变量。

Answer 3

您可以将 $sheep（您创建的对象）作为参数发送给机器类中的函数。

Answer 4

我讨厌农业。
不要只是复制意大利面。通读它，提出问题（但不能重复），我们将能够提供帮助。

interface Animal{
    const AGE_YOUNG = 0;
    const AGE_OLD = 1;
    const COLOR_WHITE = 'white';
    const COLOR_BLACK = 'black';
    public function getAge();
    public function getColor();
}

interface Shearable extends Animal{
    public function shear();
    public function isSheared();
}

class Gorilla implements Shearable{
    // ♫ seeeeeee my vest, see my vest, made of real gorilla chest ♫
}

class Sheep implements Shearable{

    private $_isSheared = false;
    private $_age = null;
    private $_color = null;

    public static function create(){
        $age = rand(0, 1);
        $color = rand(0, 1)
            ? self::COLOR_WHITE
            : self::COLOR_BLACK;
        return new self($age, $color);
    }

    public function __construct($age, $color){
        $this->_age = $age;
        $this->_color = $color;
    }

    public function shear(){
        $this->_isSheared = true;
        return $this;
    }

    public function isSheared(){
        return $this->_isSheared;
    }

    public function getAge(){
        return $this->_age;
    }

    public function getColor(){
        return $this->_color;
    }

}

class Machine{

    private $_wool = array();

    public function shearLine(Array $line){
        $unshearable = array();
        foreach($line as $animal){
            if($this->shear($animal) !== true){
                $unshearable[] = $animal;
            }
        }
        return $unshearable;
    }

    public function shear(Shearable $animal){
        if(!$animal->isSheared() && $animal->getAge() == Shearable::AGE_OLD){
            $this->_wool[] = $animal->shear()->getColor();
            return true;
        }
        return $animal;
    }

    public function getWool(){
        return count($this->_wool);
    }

    public function getWoolByColor($color){
        return count(array_keys($this->_wool, $color));
    }

}

// build a machine
$machine = new Machine();

// brew up some sheep
$lineOfSheep = array();
for($i = 0; $i < 200; $i++){
    $lineOfSheep[] = Sheep::create();
}

//make some underwear
$unshearable = $machine->shearLine($lineOfSheep);

// see how many sheep still need water and sunlight
var_dump(count($unshearable));

// see how much and of what color your underwear will be
var_dump($machine->getWool(), $machine->getWoolByColor(Shearable::COLOR_WHITE));