Question

I follow struggling with bidimensional arrays and foreach loops. The following code shows a magazines array, each of them points to an unidimensional Articles array. Right now is storing three Articles for each magazine (just the Article’s Title). I would like to know how to associate a Bidimensional array so that can I store the Author and PagesNumber besides the Title, for each article belonging a magazine. Could you point me in the right direction? Thanks in advance.

<?php

// Create a magazines array
$magazines = array();

// Put 5 magazines on it
for($x=0;$x<5;$x++)
    $magazines[] = "Magazine " . $x ;

// Associate articles array to each magazine
foreach($magazines as $magazine){
    $articles[$magazine] = array();
    for($x=0;$x<3;$x++)
        $articles[$magazine][] = $magazine . " - Article Title " . $x ;
}

// List them all
foreach($magazines as $magazine){
    echo $magazine . " has these articles: <br>";
    foreach($articles[$magazine] as $article)
        echo $article . "</br>";
}
?>

Answer 1

Maybe you should structure it a little different:

$magazines = array();

//create magazines
for($x=0;$x<5;$x++) {
  $magazines[] = array('name' => 'Magazine ' . $x, 
                       'year' => '2011', 
                       'articles' => array());
}

//fill in some articles
foreach ($magazines as &$magazine) {
  for($x=0;$x<3;$x++) {
    $magazine['articles'][] = array('article_titel' => $magazine['name'] . " - Article Title " . $x, 
                                    'article_author' => 'author ' . $x,
                                    'article_page' => $x);
  }
}

//output
foreach($magazines as $magazine) {
  echo 'The Magazine ' . $magazine['name'] . ' from ' . $magazine['year'] . ' contains the articles : ';
  foreach($magazine['articles'] as $article) {
    echo $article['article_titel'] . ' by ' . $article['article_author'] . ' on page ' . $article['article_page'];
  }
}

A little explaination:
Magazines is a normal array.
Then you add associative arrays to it (magazines).
Each magzines-array has an articles-field, which is a normal array, which you add associative arrays to again (articles).

So now, you iterate throug magazines, and each magazine has an array of articles which you can iterate.

That means: Magazines is an array of single magazines, one magazine is an associative array, which also contains an array of articles. An article is an associative array again.

I hope that sounds not too confusing… 😉