woocommerce_format_weight │ filter-hook │ WC 1.0

Usage

add_filter( 'woocommerce_format_weight', 'wp_kama_woocommerce_format_weight_filter', 10, 2 );

/**
 * Function for `woocommerce_format_weight` filter-hook.
 * 
 * @param  $weight_string 
 * @param  $weight        
 *
 * @return 
 */
function wp_kama_woocommerce_format_weight_filter( $weight_string, $weight ){

	// filter...
	return $weight_string;
}

$weight_string

-

$weight

-

Where the hook is called

return apply_filters( 'woocommerce_format_weight', $weight_string, $weight );

Where the hook is used in WooCommerce