product_type_options get saved value [closed]

I have modified your code please check the below code.

 function add_octopus_child_option( $product_type_options ) {
    $product_type_options['childocto'] = array(
      'id'            => '_childocto',
      'wrapper_class' => 'show_if_octopus',
      'label'         => __( 'Gekoppeld', 'woocommerce' ),
      'description'   => __( 'Vink dit aan indien dit niet het hoofdproduct is.', 'woocommerce' ),
      'default'       => 'no'
   );
   return $product_type_options;
 } 
 add_filter( 'product_type_options', 'add_octopus_child_option' );

 function save_product_data_octopus($post_id){
    $woocommerce_checkbox = isset( $_POST['_childocto'] ) ? 'yes' : 'no';
    update_post_meta( $post_id, '_childocto', $woocommerce_checkbox );
 }
 add_action( 'woocommerce_process_product_meta_simple','save_product_data_octopus'  );
 add_action( 'woocommerce_process_product_meta_variable', 'save_product_data_octopus'  );

Try with the above code and if does not work let me know.