How to make a Nested List from array in PHP (noob)

Question

I have an app that users choose items and then it fills a table that has two columns in it: Category and Items. Its something like this:

Category  | Items 
-----------------
PET       | Dog Food
HEALTH    | Tooth Brush
PET       | Cat Food
COLD FOOD | Steak
COLD FOOD | Eggs

In my select statement I order the data by Category then by Items and I am using a WHILE loop to drop the data into an array.

while($listItems = mysql_fetch_array($results))
{
    $myArray[] = array("category" => $listItems["Category"],
                       "item"     => $listItems["Name"]);
}

When I do a print_r($myArray); I get something like this:

Array ( [0] => Array ( [category] => Cold Food [item] => Steak )
        [1] => Array ( [category] => Food      [item] => Eggs )
        [2] => Array ( [category] => Health    [item] => Tooth Brush )
        [3] => Array ( [category] => Pet       [item] => Cat Food )
        [4] => Array ( [category] => Pet       [item] => Dog Food ) )

What I am wanting to do is output the data into a nested list something like this.

Cold Food

Steak
Eggs

Health

Tooth Brush

Pet

Cat Food
Dog Food

Any help is welcomed! Thanks!

possible duplicate of PHP function that creates a nested ul li? — Alister Bulman
– Alister Bulman, Commented Feb 11, 2011 at 21:46

Jacob Relkin · Accepted Answer · 2011-02-11 22:19:41Z

4

Try this:

while($listItems = mysql_fetch_array($results))
{
    $cat  = $listItems['Category'];
    $name = $listItems['Name'];

    if(!isset($myArray[$cat]))
      $myArray[$cat] = array();

    $myArray[$cat][] = $name;
}

Then, to output it you'd do this:

$buffer = '<ul>';
foreach($myArray as $cat => $items) {
   $buffer .= "<li>$cat</li><li><ul>";
   foreach($items as $item) {
      $buffer .= "<li>$item</li>";
   }
   $buffer .= '</ul></li>';
}
$buffer .= '</ul>';
echo $buffer;

edited Feb 11, 2011 at 22:19

answered Feb 11, 2011 at 21:43

Jacob Relkin

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1 Comment

Cornfed Over a year ago

Jacob you rock. I been scratching my head on this for weeks and you nailed it in 13mins. The only change I had to make was on the second "$buffer". I changed it from $buffer .='<li><ul>'; to $buffer .='<li>'.$cat.'</li><ul>';

John Kugelman · Accepted Answer · 2011-02-11 21:48:00Z

1

Give this a try. The idea is to reorganize your data into a more convenient form, namely to have the items indexed by category.

Code

<?php
    $items = array
    (
        array('category' => 'Cold Food', 'item' => 'Steak'),
        array('category' => 'Food', 'item' => 'Eggs'),
        array('category' => 'Health', 'item' => 'Tooth Brush'),
        array('category' => 'Pet', 'item' => 'Cat Food'),
        array('category' => 'Pet', 'item' => 'Dog Food'),
    );

    // Group the items by category.
    $itemsByCategory = array();

    foreach ($items as $item)
    {
        $category = $item['category'];
        $name     = $item['item'];

        if (!array_key_exists($category, $itemsByCategory))
            $itemsByCategory[$category] = array();

        $itemsByCategory[$category][] = $name;
    }

    // Output nested lists for the items.
?>  <ul>
<?php foreach ($itemsByCategory as $category => $items)
      {
?>        <li><?php echo htmlspecialchars($category); ?>

              <ul>
<?php           foreach ($items as $item)
                {
?>                  <li><?php echo htmlspecialchars($item); ?></li>
<?php           }
?>            </ul>
          </li>
<?php }
?>  </ul>

Output

Cold Food

Steak

Food

Eggs

Health

Tooth Brush

Pet

Cat Food

Dog Food

answered Feb 11, 2011 at 21:48

John Kugelman

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2 Comments

Jacob Relkin Over a year ago

This would work, but don't you think it'd be DRYer to have a nested array?

jrn.ak Over a year ago

doesn't asort($items) save you from creating an entire new array?

user606087 · Accepted Answer · 2011-02-11 22:24:12Z

1

<?
//establish $vlink before
$query = 'select distinct (category) from list';
$result = mysql_query($query,$vlink);

while($row = mysql_fetch_array($results))
{
    $query1 = "select items from list where category = ".$row[0];
    $result1 = mysql_query($query1,$vlink);

    echo '<h1>'.$row[0].'</h1>';
    while($row1 = mysql_fetch_array($result1))
    {
        echo '<h2>'.$row1[0].'</h2>';
    }
}
?>

answered Feb 11, 2011 at 22:24

user606087

Comments

mpj.dev · Accepted Answer · 2011-02-11 21:44:34Z

0

Try with this:

while($listItems = mysql_fetch_array($results)) 
{
     $myArray[$listItems["Category"]][] = $listItems["Name"] 
}

answered Feb 11, 2011 at 21:44

mpj.dev

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