PHP sort array of objects by two properties

Question

I have an array

Array
(
[0] => stdClass Object
    (
        [tab_option_name_selector] => 2
        [fieldtype] => notes
        [order] => 12
    )

[1] => stdClass Object
    (
        [tab_option_name_selector] => 2
        [fieldtype] => notes
        [order] => 8
    )

[2] => stdClass Object
    (
        [tab_option_name_selector] => 1
        [order] => 2
        [fieldtype] => selectbox
    )

[3] => stdClass Object
    (
        [tab_option_name_selector] => 2
        [order] => 3
        [fieldtype] => selectbox
    )
)

I'm trying to get this usort function to work

function osort(&$array, $props) 
{ 
    if(!is_array($props)) 
        $props = array($props => true); 

    $me = usort($array, function($a, $b) use ($props) { 
        foreach($props as $prop => $ascending) 
        { 
            if($a->$prop != $b->$prop) 
            { 
                if($ascending) 
                    return $a->$prop > $b->$prop ? 1 : -1; 
                else 
                    return $b->$prop > $a->$prop ? 1 : -1; 
            } 
        } 
        return -1; //if all props equal        
    });    
    print_r($props);
    return ($me);
} 


$tab = osort($objectArray, "tab_option_name_selector", "order"); 

so sorting by the tab then order.

$tab is empty - any ideas what I'm doing wrong?

Answer 1

Why the extra level of indirection and making things more confusing? Why not usort directly with usort($objectArray, "sortObjects"); using a sortObjects($a,$b) function that does what any comparator does: return negative/0/positive numbers based on the input?

If the tabs differ, return their comparison, if they're the same, return the order comparison; done.

$array = array(
    (object)array(
        'tab_option_name_selector' => 2,
        'fieldtype' => 'notes',
        'order' => 12
    ),
    (object)array(
        'tab_option_name_selector' => 2,
        'fieldtype' => 'notes',
        'order' => 8
    ),
    (object)array(
        'tab_option_name_selector' => 1,
        'order' => 2,
        'fieldtype' => 'selectbox'
    ),
    (object)array(
        'tab_option_name_selector' => 2,
        'order' => 3,
        'fieldtype' => 'selectbox'
    )
);

function compareTabAndOrder($a, $b) {
    // compare the tab option value
    $diff = $a->tab_option_name_selector - $b->tab_option_name_selector;
    // and return it. Unless it's zero, then compare order, instead.
    return ($diff !== 0) ? $diff : $a->order - $b->order;
}

usort($array, "compareTabAndOrder");
print_r($array);