{
  A.AMethod( B b ) {
    b.BMethod();
    /*….*/
  }
}

{
  A.AMethod( I i ) {
    i.Method();
  }
}

<?php
interface Calculation {
  function compute($a, $b);
}
class Addition implements Calculation {
  function compute($a, $b)
  {
    return "加法運(yùn)算結(jié)果為:".($a+$b);
  }
}
class Subtraction implements Calculation {
  function compute($a, $b)
  {
    return "減法運(yùn)算結(jié)果為:".($a-$b);
  }
}
class Multiplication implements Calculation {
  function compute($a, $b)
  {
    return "乘法運(yùn)算結(jié)果為:".($a*$b);
  }
}
class Division implements Calculation{
  function compute($a, $b)
  {
    return "除法運(yùn)算結(jié)果為:".($a/$b);
  }
}
class Modf implements Calculation {
  function compute($a, $b)
  {
    return "取模運(yùn)算結(jié)果為:".($a % $b);
  }
}
class Coupling implements Calculation {
  //這里直接：public $varl = new LazyDog(); 會(huì)出錯(cuò)。
  public $varl = null;
  function __construct()
  {
    $this->varl = new LazyDog();
  }
  function compute($a, $b)
  {
    return $this->varl->say();
  }
}
/*也可以用繼承的方式實(shí)現(xiàn)喲:
class Coupling extends LazyDog implements Calculation {
  function compute($a, $b)
  {
    return parent::say();
  }
}
*/
class LazyDog {
  function say()
  {
    return "我什么運(yùn)算都不做...只是為了實(shí)現(xiàn)'耦合設(shè)計(jì)模式'...我是出來打醬油的......";
  }
}
class Test {
  private $one;
  private $two;
  public function __construct($x,$y)
  {
    $this->one=$x;
    $this->two=$y;
    echo "Class Test 初始化：屬性\$one=".$this->one."，屬性\$two=".$this->two."<hr />";
  }
  function display(Calculation $a){
    return "用PHP接口技術(shù)實(shí)現(xiàn)的運(yùn)算：".$a->compute($this->one,$this->two)."<hr />";
  }
}
$t = new Test(96,12);
$t1 = new Addition();
$t2 = new Subtraction();
$t3 = new Multiplication();
$t4 = new Division();
$t5 = new Modf();
$dog = new Coupling();
echo $t->display($t1);
echo $t->display($t2);
echo $t->display($t3);
echo $t->display($t4);
echo $t->display($t5);
echo $t->display($dog);
?>