数组乘以答案并返回它

This is what I am trying to do. I would like my code to return the following:

"The volume of the small box is: 300"

But I cannot seem to figure out what to do:

<?php
    $box = array(
       "Small box" => array("length" => 12, "width" => 10, "depth" => 2.5),
       "Medium box" => array("length" => 30, "width" => 20, "depth" => 4),
       "Large box" => array("length" => 60, "width" => 40, "depth" => 11.5)

    );
    foreach ($box as $number => $boxes)
    {
        echo "The volume of the "."$number"." is: \t";
        foreach ($boxes as $value)            
        {
            if (is_numeric($value))
            {
               $sum = array_product($boxes);
               echo "$sum";
            }
        }
        echo "<br />";
    }
    ?>

You are looping through the $value, calculating and displaying the $sum multiple (3) times. Just calculate the product:

foreach ($box as $number => $boxes)
{
    echo "The volume of the "."$number"." is: \t";
    echo array_product($boxes);

    echo "<br />";
}

If you don't have a predictable array with length, width and depth then there is little point in doing this at all, but you could also do:

    echo $boxes['length'] * $boxes['width'] * $boxes['depth'];

$box = array(
    "Small box" => array("length" => 12, "width" => 10, "depth" => 2.5),
    "Medium box" => array("length" => 30, "width" => 20, "depth" => 4),
    "Large box" => array("length" => 60, "width" => 40, "depth" => 11.5)
);

foreach ($box as $key => $boxes) {
    $volume = array_product($boxes);
    echo "The volume of the $key is: $volume
";
}

you can get size of box into index array

 $sum = 1;/*set variable sum to 1 so if it's * in another numerics it's not 0*/
 $i = 0; /*set i condition to reset value of condition*/
    foreach ($box as $number => $boxes) { 
        foreach ($boxes as $value)            
        {
            if (is_numeric($value)){
               $sum = $sum*$value; /*it's product length*width*depth */
            }
            /*cek the condition if count of boxes is limit lengt so define variable data["box type"]*/
            if(($i+1) == count($boxes)){
              $data[$number] = $sum; /*give value for $data["box type"]*/
            }
            $i++;
        }
        $sum = 1;/*reset sum to 1*/
        $i   =0;/*reset i to 0*/
    }

this the result of print_r($data);

Array
(
    [Small box] => 300
    [Medium box] => 2400
    [Large box] => 27600
)

and you can access the variable to any type of box using.

echo "sample : The volume of the Medium Box is ". $data["Medium box"]." : \t";

and the result will be like

sample : The volume of the Medium Box is 2400

let me know if this you looking for.