Update all variations prices of a variable product in Woocommerce

I need to get all variation id and update price in loop. Simple query and loop looks like:

$params = array(
  ‘posts_per_page’ => -1,
  ‘post_type’ => ‘product_variation’,
  ‘post_parent’ => $product->get_id() // tried $post-ID
);
$variations = get_posts( $params );
foreach ( $variations as $variation ) {
  $variation_ID = $variation->ID; // tried $post-ID, $product->get_id()
  $regular_price=34;
  update_post_meta( $variation_ID, ‘_regular_price’, (float)$regular_price );
  update_post_meta( $variation_ID, ‘_price’, (float)$regular_price );
}

I think not working this:

(‘post_parent’ => $product->get_id()) 

or this:

($variation_ID = $variation->ID;). 

Answer

First in your code ‘ or ’ should be replaced by '. Also if used $post-ID should be replaced by $post->ID

Depending on where and how you are using this code, you should try to include global $post; first to be able to use the WP_Post object $post.

Then you could try to use this customized version of your code instead:

global $post;

$regular_price = 13;

// Only for product post type
if( $post->post_type == 'product' )
    $product = wc_get_product( $post->ID ); // An instance of the WC_Product object

// Only for variable products
if( $product->is_type('variable') ){

    foreach( $product->get_available_variations() as $variation_values ){
        $variation_id = $variation_values['variation_id']; // variation id
        // Updating active price and regular price
        update_post_meta( $variation_id, '_regular_price', $regular_price );
        update_post_meta( $variation_id, '_price', $regular_price );
        wc_delete_product_transients( $variation_id ); // Clear/refresh the variation cache
    }
    // Clear/refresh the variable product cache
    wc_delete_product_transients( $post->ID );
}

This code is tested on WooCommerce version 3+ and works