Menu Submenu with PHP Classes and Objects - php

Question

I need to make a menu with a submenu. Menu 'id' => 'parent1' = submenu 'parent' => 'parent1'.
If parent has no child echo only parent. If parent has childrens insert all children inside parent. Maybe try with a for loop, or some other solution?
If a child exists, each submenu child should be inserted in its parent by id. How?
The code example should echo:
<div class="menu" href="myurl">Parent 1
<div class="submenu" href="myurl">Child 1</div>
<div class="submenu" href="myurl">Child 2</div>
</div>
<div class="menu" href="myurl">Parent 2
<div class="submenu" href="myurl">Child 3</div>
</div>
class menu {
public $id;
public $parent;
public $name;
public $url;
public function add_node($args) {
echo '
<div class="menu" href="' . $args['url'] . '">' . $args['name'] . '
<div class="submenu" href="' . $args['url'] . '">' . $args['name'] . '</div>
</div>';
}
}
if (class_exists('menu')){
global $menu;
$menu = new menu();
}
function menu_parent_child(){
$args = array(
'id' => 'parent1',
'name' => 'Parent 1',
'url' => 'myurl'
);
$args = array(
'parent' => 'parent1',
'name' => 'Child 1',
'url' => 'myurl'
);
$args = array(
'parent' => 'parent1',
'name' => 'Child 2',
'url' => 'myurl'
);
$args = array(
'id' => 'parent2',
'name' => 'Parent 2',
'url' => 'myurl'
);
$args = array(
'parent' => 'parent2',
'name' => 'Child 3',
'url' => 'myurl'
);
}