Sort array in array in array in PHP

Question

I have array like this:

$items = array(
              [1] => array(
                           ['Name']   =>"Item 1", 
                           ['Prices'] => array(
                                               ['Base price'] => 80.25,
                                               ['Discount'] => 5.50
                                              )
                          ),

              [2] => array(
                           ['Name']   =>"Item 2", 
                           ['Prices'] => array(
                                               ['Base price'] => 70.25,
                                               ['Discount'] => 4.50
                                              )
                          )
              );

How can I sort $items that by "Base price"? I want to have lowest price in first element, highest in last element of output array with same structure.

Expected output:

$items = array(
               [1] => array(
                           ['Name']   =>"Item 2", 
                           ['Prices'] => array(
                                               ['Base price'] => 70.25,
                                               ['Discount'] => 4.50
                                              )
                          ),
               [2] => array(
                           ['Name']   =>"Item 1", 
                           ['Prices'] => array(
                                               ['Base price'] => 80.25,
                                               ['Discount'] => 5.50
                                              )
                          )
              );

I don't understand array_multisort() and how to use it in my case.

Answer 1

This is how you could use array_multisort :

foreach ($items as $item) {
    $sort[] = $item['Prices']['Base price'];
}

array_multisort($sort, SORT_ASC, $items);

Like Jan was saying, you can also use usort :

usort($items, function($a, $b) {
    return $a['Prices']['Base price'] - $b['Prices']['Base price'];
});

Answer 2

I hope this helps. I'm using usort() with a callback function:

$arr = array(
    array(
        'foo' => 'bar',
        'data' => array(
            'basePrize' => 5
        )   
    ),
    array(
        'foo' => 'bar2',
        'data' => array(
            'basePrize' => 2
        )
    )
);

usort($arr, function($a, $b) {
    if($a['data']['basePrize'] === $b['data']['basePrize']) {
        return 0;
    }   

     if($a['data']['basePrize'] > $b['data']['basePrize']) {
        return 1;
    }   

    return -1
});