How to Get Configurable product children ids Magento 2?

Get all the children product ids from the Configurable product in Magento 2. You can retrieve the list of child item ids by the configurable product id.

Get all Children items of Bundle Products Magento 2.

To fetch all the children items from the configurable product, get Configurable product id and pass it to the method in given code,

<?php
namespace Jesadiya\ChildIds\Model;

use Magento\ConfigurableProduct\Model\Product\Type\Configurable;

class ConfigurableChildrenIds
{
    /**
     * @var Configurable
     */
    private $configurable;

    public function __construct(
        Configurable $configurable
    ) {
        $this->configurable = $configurable;
    }

    /**
     * Get Children items id by the parent id
     *
     * @param int $id
     *
     * @return array
     */
    public function getChildrenIds(int $id)
    {
        $childItemId = $this->configurable->getChildrenIds($id);
        return $childItemId;
    }
}

Call from the PHP class,

$configurableId = 2046;
$superAttributeByChild = $this->getChildrenIds($configurableId);

List of all the children items id for a configurable product.

Output:
Array