PHP按字母顺序排序

Question

I'm struggling on this one. I have an array that contains countries and regions. I want to sort both sets of information in ascending order on the key.

Here is the array I'm working with:

Array
(
    [Country] => Array
        (
            [United Kingdom] => Array
                (
                    [London] => Array
                        (
                            [0] => 1
                            [1] => 5
                            [2] => 23
                            [3] => 71
                        )

                    [Manchester] => Array
                        (
                            [0] => 800
                        )

                )

            [United States] => Array
                (
                    [New York] => Array
                        (
                            [0] => 147
                            [1] => 111
                        )

                    [Washington] => Array
                        (
                            [0] => 213
                        )

                    [Florida] => Array
                        (
                            [0] => 6
                        )

                    [Texas] => Array
                        (
                            [0] => 9
                        )

                )

            [Brazil] => Array
                (
                    [Brasília] => Array
                        (
                            [0] => 64
                        )

                )

        )

)

So the reordered array would be:

Brazil
- Brasília

United Kingdom
- London
- Manchester

United States
- Florida
- New York
- Texas
- Washington

The data structure should remain the same, but the order of the number (eg London: 1,5,23,71) can stay the same.

I've tried several of the sorting methods from: http://php.net/manual/en/array.sorting.php

But they dont appear to do anything. Maybe because its a multidimensional array or maybe its not structured 100% logically... but I'm stuck with the array as it is.

Answer 1

You can try:

ksort_recursive($data);
print_r($data);

Function Used

function ksort_recursive(&$array) {
    ksort($array);
    foreach ( $array as &$a ) {
        is_array($a) && ksort_recursive($a);
    }
}

See Testing on Multiple PHP Versions

Answer 2

Step 1:
Sort the country by key.

ksort($arr['Country']);

Step 2: Loop through the countries and sort those keys.

foreach ($arr['Country'] as $country=>$data) {
    ksort($arr['Country'][$country]);
}