Connecting Wordpress scripts?

Question

JavaScript

I can't connect scripts, what's wrong?
function damdar_js() {
wp_register_script( 'jquery', ' ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js ');
wp_enqueue_script( 'jquery', ' ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js ' );
wp_register_script('damdar_script', get_template_directory_uri() . '/js/index.js', array(jquery), 'null' , true );
wp_enqueue_style( 'damdar_script', get_template_directory_uri() . '/js/index.js', array(jquery), 'null' , true );
wp_register_script( 'damdar_ajax.js', ' https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.... ', array(jquery), 'null', true );
wp_enqueue_script( 'damdar_ajax.js');
}
add_action('wp_enqueue_scripts', 'damdar_js');

Help plz