基于索引的php数组的自定义顺序

I have PHP array that looks like

$my_arr['cats'] = array('Shadow', 'Tiger', 'Luna');
$my_arr['dogs'] = array('Buddy', 'Lucy', 'Bella');
$my_arr['dolphins'] = array('Sunny', 'Comet', 'Pumpkin');
$my_arr['lizzards'] = array('Apollo', 'Eddie', 'Bruce');
//and many more lines like this

I need to sort it based on it keys using sorting array like

$order = array('lizzards', 'cats');

I want that the first item should be lizzards array, second item - cats and then all items that were not specified in $order array. How it can be done using usort / uasort / uksort functions?

You can achieve this by below code

<?php

function sortByKey(&$arr,$key_order)
{
    if(count(array_intersect(array_keys($arr),$key_order))!=count($key_order))
    {
        return false;
    }
    $ordered_keys=array_merge($key_order,array_diff(array_keys($arr),$key_order));
    $sorted_arr=[];
    foreach($ordered_keys as $key)
    {
        $sorted_arr[$key]=$arr[$key];
    }
    $arr=$sorted_arr;
    return true;
}

$my_arr=[];
$my_arr['cats'] = array('Shadow', 'Tiger', 'Luna');
$my_arr['dogs'] = array('Buddy', 'Lucy', 'Bella');
$my_arr['dolphins'] = array('Sunny', 'Comet', 'Pumpkin');
$my_arr['lizzards'] = array('Apollo', 'Eddie', 'Bruce');

$order = array('lizzards', 'cats');

if(sortByKey($my_arr,$order){
    echo "Sorting done successfully";
}
else
{
    echo "Sorting ignored, order element miss matched";
}

print_r($my_arr);
?>

A shorter solution using uksort:

uksort($my_arr, function ($a,$b) use ($order) {
    //Look for elements indexes in the 'order' array 
    $aKey = array_search($a, $order);
    $bKey = array_search($b, $order);

    if($aKey !== FALSE && $bKey !== FALSE) {
        return $aKey - $bKey;
    } else if($aKey !== FALSE) {
        return -1;
    } else if($bKey !== FALSE) {
        return 1;
    }
    return 0;
});