如何从key返回PHP数组值？

Question

我正在尝试根据选择菜单中的城市选择生成用户的国家/地区。 我使用关联数组生成了选择菜单。 我想打印“$ city in $ country”但我无法正常访问$ country。 这就是我所拥有的：

<?php
$cities = array("Tokyo" => "Japan", "Mexico City" => "Mexico", 
"New York City" => "USA", "Mumbai" => "India", "Seoul" => "Korea",
"Shanghai" => "China", "Lagos" => "Nigeria", "Buenos Aires" => "Argentina", 
"Cairo" => "Egypt", "London" => "England");
?>

<form method="post" action="5.php">
<?php
echo '<select name="city">';

foreach ($cities as $city => $country)
{
echo '<option value="' . $city . '">' . $city . '</option>';
}

echo '<select>';

?>

<input type="submit" name="submit" value="go" />
</form>
<?php
$city = $_POST["city"];

print ("$city is in $country");
?>

有任何想法吗？ 谢谢。

Answer 1

您正试图从foreach循环中访问本地foreach变量$ country。 你必须在循环中做到这一点。

或者你可以从城市阵列获得这样的国家：

$cities[$city];

Answer 2

...
<?php
$city = $_POST["city"];

print ("$city is in ".$cities[$city]);
?>