function bombardStrength()
{
$ret = 0;
foreach ($this->units as $unit) {
$ret += $unit->bombardStrength();
}
return $ret;
}
}
class UnitException extends Exception
{
}
class Archer extends Unit
{
function addUnit(Unit $unit)
{
throw new UnitException(get_class($this) . " is a leaf");
}
function removeUnit(Unit $unit)
{
throw new UnitException(get_class($this) . " is a leaf");
}
function bombardStrength()
{
return 4;
}
}
$archer = new Archer();
$archer2 = new Archer();
$archer->addUnit($archer2);
