how to create a custom post type in wordpress php code example

Example 1: create custom post type with category in wordpress functions.php

function create_posttype() {
  register_post_type( 'wpll_product',
    array(
      'labels' => array(
        'name' => __( 'Products' ),
        'singular_name' => __( 'Product' )
      ),
      'public' => true,
      'has_archive' => true,
      'rewrite' => array('slug' => 'products'),
    )
  );
}
add_action( 'init', 'create_posttype' );

Example 2: wordpress custom post type Query

<?php 
    query_posts(array( 
        'post_type' => 'portfolio',
        'showposts' => 10 
    ) );  
?>
<?php while (have_posts()) : the_post(); ?>
        <h2><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></h2>
        <p><?php echo get_the_excerpt(); ?></p>
<?php endwhile;?>