Change excerpt length for different post types. WordPress code example

/**
 * Change Excerpt length for different post types.
 */
 function vishivka_custom_excerpt_length($length)
{
    global $post;
    if ($post->post_type == 'post')
        return 25;
    else if ($post->post_type == 'product')
        return 100;
    else
        return 50;
}
add_filter('excerpt_length', 'vishivka_custom_excerpt_length');