php switch语句使用文本框/下拉框

Question

I am trying to use a switch statement to make it so that when that specific word is typed into the text box it will display the available models of that car

for example

if the user entered "Volkswagen" it should echo "The available models are Beetle and Polo"

But for some reason it isnt working can anyone suggest to me why?

here is the code i have so far,

<form action="switch.php" method="post">

    <input type="text" name="cars" id="cars" />
       <input type="submit" /> 
<?php
$i = $_POST;
?>

<?php
switch ($i) {
    case "Volkswagen":
        echo "The available models are Beetle and Polo";
        break;
    case "Renault":
        echo "The Available models are Megane and Clio";
        break;
    case "Land Rover":
        echo "The Available models are Range Rover Sport and Defender";
        break;
}
?>
</form> 

EDIT:

I am a bit stuck now i am trying to use this switch statement with a drop down box and not quite sure how i can make them work together if anyone can help me to make them work together that would be great

this is the code I have for the working switch and a working drop box.

<form action="">
<select name="cars">
<option value="Volkswagen">Volkswagen</option>
<option value="Renault">Renault</option>
<option value="Land Rover">Land Rover</option>
</select>


<p>
<?php
switch($_POST['cars']) {
    case "Volkswagen":
        echo "The available models are Beetle and Polo";
        break;
    case "Renault":
        echo "The Available models are Megane and Clio";
        break; 
    case "Land Rover":
        echo "The Available models are Range Rover Sport and Defender";
        break;
}
?>
</p>
</form>
</center>

Answer 1

$_POST is an array. It is NOT something you can compare against strings. PHP will convert the array to the literal word Array. Since you don't have a case with that word, you get no matches at all.

Form values are submitted as elements of the $_POST array. You should be doing

switch($_POST['cars']) {
   ...
}

instead