Wordpress - Get all posts of a custom type 'campaign' #wordpress

wp_get_all_posts_of_a_type.php

    $loop = new WP_Query( array(
        'post_type' => 'campaign',
        'posts_per_page' => -1,     // It will return all posts.
    ));

    while ( $loop->have_posts() ) {
        $loop->the_post();
        $post_id = get_the_ID();
        $post_title = get_the_title();
    }