警告：来自多维数组的非法字符串偏移

Question

In the code below, I am trying to use echo $r_id[$d_id]['name'];" where $r_id = china and $d_id = china1 was defined in a previous page, so as to replicate echo $china['china1']['name'];, which will give me the value of Beef and Broccoli from the array.

<?php
$china = array(
'china1'=> array(
'cat'=> "Chinese",
'id'=>"C1",
'name'=>"Beef and Broccoli",
'instruction'=> "Placeholder")
);

if(isset($_GET["r_id"])){
        if(isset($_GET["d_id"])){
            $r_id = $_GET["r_id"];
            $d_id = $_GET["d_id"];
        }
    }

    echo $r_id[$d_id]['name'];

?>

But all I am getting is this:

Warning: Illegal string offset 'china1' in....

Warning: Illegal string offset 'name' in....

Where did I get it wrong? Code for the previous page:

        <table border = 1px align = center style = "margin-top:100px;">
        <tr>
            <td><a href="recipes.php?r_id=china&d_id=china1"><img src="images/china1icon.jpg"/></a></td>
            <td><img src="images/vietnam1icon.jpg"/></td>
            <td><img src ="images/japan1icon.jpg"/></td>
            <td><img src ="images/korea1icon.jpg"/></td>
        </tr>
    </table>

Answer 1

You cannot pass a variable directly into the URL: <a href="recipes.php?r_id=$china&d_id=china1"></a>. You should print out the variable in the URL like <a href="recipes.php?r_id=" . $china . "&d_id=china1"></a>, and then it'd work.

And on this page, $r_id is now 'china', if you want echo $r_id[$d_id]['name']; to become echo $china['china1']['name'];, then you need to do $$r_id[$d_id]['name'], note the double dollar sign, which defines a variable variable.