recursive-parent-child-menu.php

<?php
$menu_array = [
    [
      'id' => 1,
      'nav_name' => 'test/',
      'parent_id' => 0
    ],
    [
      'id' => 2,
      'nav_name' => 'test1/',
      'parent_id' => 0
    ],
    [
      'id' => 3,
      'nav_name' => 'test2/',
      'parent_id' => 2
    ],
    [
      'id' => 4,
      'nav_name' => 'test3/',
      'parent_id' => 2
    ],
    [
      'id' => 5,
      'nav_name' => 'test4/',
      'parent_id' => 4
    ],
];

function buildMenuFromArray($menu_array, $parent_id = 0, $parentClass = "", $subClass = "")
{

    $childItems = array();
    foreach ($menu_array as $key => $item)
    {
   
        if ($item['parent_id'] == $parent_id)
        {
            $childItems[] = $item;
            unset($menu_array[$key]);
        }
    }
     
    if ($childItems)
    {
        echo "<ul class='{$parentClass}'>";
        foreach ($childItems as $key => $item)
        {
            echo '<li>'.$item['nav_name'];
            buildMenuFromArray($menu_array, $item['id'], $subClass, $subClass);
            echo '</li>';
        }
        echo '</ul>';
    } else {
      echo "<ul class='{$subClass}'></ul>";
    }
}

buildMenuFromArray($menu_array, 0, 'nav-table', 'sub');