为什么这样的二维数组foreach后只有最后一个值输入?

$res = array(
array(
'goods_id' => 14,
'goods_number' => 1
),
array(
'goods_id' => 16,
'goods_number' => 1
),
array(
'goods_id' => 18,
'goods_number' => 1
)
);
上面数组，我想遍历出goods_id 从14 到 18，也就是14,15,16,17,18 ，从而得到goods_id 对应的 goods_number，如果goods_id不存在数组里，goods_number就给予0给它。

foreach($res as $value)
{
if($value['goods_id'] == 14)
{
echo $value['goods_number'];
echo "
";
}
else
{
echo 0;
echo "
";
}

if($value['goods_id'] == 15)
{
echo $value['goods_number'];
}
else
{
echo 0;
echo "
";
}

if($value['goods_id'] == 16)
{
echo $value['goods_number'];
}
else
{
echo 0;
echo "
";
}

if($value['goods_id'] == 17)
{
echo $value['goods_number'];
}
else
{
echo 0;
echo "
";
}

if($value['goods_id'] == 18)
{
echo $value['goods_number'];
}
else
{
echo 0;
echo "
";
}
}
为什么我这样foreach 不行呢？

我要的结果是：
goods_id：14 时 goods_number：1
goods_id：15 时 goods_number：0
goods_id：16 时 goods_number：1
goods_id：17 时 goods_number：0
goods_id：18 时 goods_number：1
所以应该echo的结果是
1
0
1
0
1

为什么我的foreach 得到的不是这样的结果呢？

回复讨论(解决方案)

$res = array(	array(		'goods_id' => 14,		'goods_number' => 1		),	array(		'goods_id' => 16,		'goods_number' => 1		),	array(		'goods_id' => 18,		'goods_number' => 1		)	);$newArr = array();foreach ($res as $key => $value) {	$newArr[$value['goods_id']] = $value['goods_number'];}//var_dump(array_values($res));exit;$range = range(14, 18);foreach ($range as $keys => $values) {	if(array_key_exists($values, $newArr)){		echo 'goods_id:'.$values.' 时 goods_number:'.$newArr[$values];		echo '
';	}else{			echo 'goods_id:'.$values.' 时 goods_number:0';		echo '
';	}}

$res = array(	array(		'goods_id' => 14,		'goods_number' => 1		),	array(		'goods_id' => 16,		'goods_number' => 1		),	array(		'goods_id' => 18,		'goods_number' => 1		)	);$newArr = array();foreach ($res as $key => $value) {	$newArr[$value['goods_id']] = $value['goods_number'];}//var_dump(array_values($res));exit;$range = range(14, 18);foreach ($range as $keys => $values) {	if(array_key_exists($values, $newArr)){		echo 'goods_id:'.$values.' 时 goods_number:'.$newArr[$values];		echo '
';	}else{			echo 'goods_id:'.$values.' 时 goods_number:0';		echo '
';	}}

学习了。

$res = array(  array( 'goods_id' => 14, 'goods_number' => 1 ),  array( 'goods_id' => 16, 'goods_number' => 1 ),  array( 'goods_id' => 18, 'goods_number' => 1 ));for($i=14; $i';}