SPL基础接口之Countable、OuterIterator

//Countable

class CountMe implements Countable

{

protected $myCount = 3;

public function count()

{

return $this->myCount;

}

}

$obj = new CountMe();

echo count($obj);

//OuterIterator

$array = ['value1','value2','value3','value4'];

$outerObj = new OuterImp(new ArrayIterator($array));

foreach ($outerObj as $key => $value) {

echo "++" . $key . "-" . $value . "\n";

}

class OuterImp extends IteratorIterator

{

public function current()

{

return parent::current() . "_tail";

}

public function key()

{

return "prev" . parent::key();

}

}