如何在PHP（noob）中从数组创建嵌套列表

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!

Answer 1

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;