functions.php

/**-------------------------------------------------
 * @package Code Snippets
 * @link http://rhythmshahriar.com/codes/
 * @author Rhythm Shahriar <[email protected]>
 * @link http://rhythmshahriar.com
 * @copyright Copyright © 2017, Rhythm Shahriar
---------------------------------------------------*/

if( !is_admin()){
    $url = 'http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js';
    $test_url = @fopen($url,'r');
    if($test_url !== false) {
        function load_external_jQuery() {
            wp_deregister_script('jquery');
            wp_register_script('jquery', '//ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js');
            wp_enqueue_script('jquery');
        }
        add_action('wp_enqueue_scripts', 'load_external_jQuery');
    } else {
        function load_local_jQuery() {
            wp_deregister_script('jquery');
            wp_register_script('jquery', get_template_directory_uri() . '/assets/js/jquery-1.11.1.min.js', __FILE__, false, '1.11.1', true);
            wp_enqueue_script('jquery');
        }
        add_action('wp_enqueue_scripts', 'load_local_jQuery');
    }
}