嵌套匹配

array_reduce.php

<?php
    $a = [
        '1,2',
        '3',
        '4',
        '5,6'
    ];
    
    $hash = [
        1 => 'xxx1',
        2 => 'xxx2',
        3 => 'xxx3',
        4 => 'xxx4',
        5 => 'xxx5',
        6 => 'xxx6',
    ];
    
    foreach ($a as $key => $id) {
        $idArray = explode(',', $id);
        $nickname = '';
        $name = array_reduce($idArray, function($nickname, $id) use($hash){
            $tmp = isset($hash[$id]) ? $hash[$id] :"";
            return $nickname = $nickname .','.$tmp;
        }, '');
    
        echo $id, "|", trim($name, ',');
        echo PHP_EOL;
    }