替换关联数组中的值？

Question

I have this:

foreach ($books as $book)
{
    $catname = get_category_name($book['category']);
    $book['category'] = $catname;
}
print_r($books);

Right now, $book['category'] represents an integer value, which references the ID of a row in a category table of the database (e.g. ID 1 = Fiction). As you can guess, get_category_name($id) takes an ID and finds the correct row, and returns the name of the category. The function works correctly, and if i print_r($catname) in the foreach it prints the names of the categories, like it should.

I have an associative array called $books that gets filled from every row in the book table in the database. What I want to do, is take the category integer value of each book element and use get_category_name($id) to replace that integer value with the actual category name.

The problem I am having is that I cannot replace the integer value that already exists at $book['category'] with the actual category name which resides in $catname. When I use print_r($books) to see if the changes were made in the foreach, they confirm the changes do not get made.

How can I fix this?

Answer 1

I think you want something like this?

foreach ($books as &$book)
{
    $catname = get_category_name($book['category']);
    $book['category'] = $catname;
}
print_r($books);

Notice the &$book.