如何在php中对Unicode序列的单词进行排序？

Question

示例：

'柠檬橙香蕉苹果'--->'elmno aegnor aaabnn aelpp'
'лимонапельсинбананяблоко'--->'илмноаеилнпсьаабннбклооя'
'αβγαβγαβγαβγαβγ'--->'ααββγγαααβββγγγ'

Answer 1

function array_sorting（$ string）{

// Split string sequence into array elements
$string = explode(" ", $string);
//print_r($string);

foreach($string as $str) {

    // Converting words into array elements
    $results = array();
    preg_match_all('/./u', $str, $results);

    foreach ( $results as $array ) {

        // Sorting array elements
        sort($array);

        // Concat elements back to words
        foreach($array as $val){
            echo $val;
        }
    }
    // Concat words back to sequence
    echo " ";
}

}

array_sorting（'αβγαβγαβγαβγαβγ'）;