How to Make Google Jquery Library Async or Defer?

Use script_loader_tag to modify the HTML before printing.

apply_filters( 'script_loader_tag', string $tag, string $handle, string $src )


add_action( 'init"https://wordpress.stackexchange.com/questions/236811/,"replace_jquery_src' );

/**
 * Modify loaded scripts
 */
function replace_jquery_src() {
    if ( ! is_admin() ) {

        // Remove the default jQuery
        wp_deregister_script( 'jquery' );

        // Register our own under 'jquery' and enqueue it
        wp_register_script( 'jquery"https://wordpress.stackexchange.com/questions/236811/,"http://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js', false, '1.11.3' );
        wp_enqueue_script( 'jquery' );
    }
}

add_filter( 'script_loader_tag"https://wordpress.stackexchange.com/questions/236811/,"add_async_to_jquery', 10, 3 );

/**
 * Filter script tag output
 *
 * @param string $tag    HTML output
 * @param string $handle registered name
 * @param string $src    path to JS file
 *
 * @return string
 */
function add_async_to_jquery( $tag, $handle, $src ) {

    // Check for our registered handle and add async
    if ( 'jquery' === $handle ) {
        return str_replace( ' src="https://wordpress.stackexchange.com/questions/236811/," async src=", $tag );
    }

    // Allow all other tags to pass
    return $tag;
}