Sorting an Associative Array by Column Value

Given an array of associative arrays, the task is to sort the elements based on a specific column value. For instance, consider the following array:

$inventory = array(
  array("type" => "fruit", "price" => 3.50),
  array("type" => "milk", "price" => 2.90),
  array("type" => "pork", "price" => 5.43),
);

The goal is to sort $inventory by the "price" column, resulting in:

$inventory = array(
  array("type" => "pork", "price" => 5.43),
  array("type" => "fruit", "price" => 3.50),
  array("type" => "milk", "price" => 2.90),
);

Solution using array_multisort()

To achieve this, we can use the array_multisort() function. It allows sorting multiple arrays by multiple columns.

Here's an example:

$price = array();
foreach ($inventory as $key => $row) {
    $price[$key] = $row['price'];
}
array_multisort($price, SORT_DESC, $inventory);

Alternatively, using array_column() (available since PHP 5.5.0):

$price = array_column($inventory, 'price');
array_multisort($price, SORT_DESC, $inventory);

By sorting the $price array, we indirectly sort $inventory since they share the same keys.