Wordpress - How to get an array of post data from wp_query result?

You should read the function reference for WP_Query on the WordPress codex. There you have a lot of examples to look at. If you don't want to loop over the result set using a while, you could get all posts returned by the query with the WP_Query in the property posts.

For example

$query = new WP_Query( array( 'post_type' => 'page' ) );
$posts = $query->posts;

foreach($posts as $post) {
    // Do your stuff, e.g.
    // echo $post->post_name;
}

Actually, you don't need to refuse to use while() loop. Same WP_Post Object is already stored in post property:

        $query = new WP_Query( $args );

        if ( $query->have_posts() ) {

            while ( $query->have_posts() ) {

                $query->the_post();

                // now $query->post is WP_Post Object, use:
                // $query->post->ID, $query->post->post_title, etc.

            }

        }