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PHP Build a Basic PHP Website (2018) Listing and Sorting Inventory Items Array Keys

modify the page to display each book's ISBN.

In this code challenge, we will modify the page to also display each book's ISBN.

First, we need to make the keys from the $books array accessible inside the foreach loop. Modify the foreach command so that, as it loops through the books, it loads the ISBN for each book into a working variable called $isbn. At the same time, it should continue loading the title of each book into the $book variable.

index.php
<?php

$books["978-0743261690"] = "Gilgamesh";
$books["978-0060931957"] = "The Odyssey";
$books["978-0192840509"] = "Aesop's Fables";
$books["978-0520227040"] = "Mahabharta";
$books["978-0393320978"] = "Beowulf";

?><html>
<head>
    <title>Five Great Books</title>
</head>
<body>
    <h1>Five Great Books</h1>
    <ul>
        <?php foreach($books as $book) { ?>
            <li><?php echo $book; ?></li>
        <?php } ?>
    </ul>
</body>
</html>

1 Answer

Joel Bardsley
Joel Bardsley
31,236 Points

As you'll know, foreach ($array as $array_value) doesn't assign the array keys to a variable, so for the challenge question $books as $book, the book title array value is stored in the $book variable, whereas the array key (in this case the ISBN number) doesn't get stored anywhere.

As the challenge uses an Associative array, in order to assign both the array keys and values to separate variables, you can modify the foreach loop as follows: foreach ($array as $array_key => $array_value)

As the question states to store the ISBN number in a $isbn variable, this can be applied as follows:

<?php
  foreach ($books as $isbn => $book) {
    // $isbn contains the ISBN number (array key) for each book
    // $book still contains the title (array value) for each book
  }
?>

Hope that helps.