How to add the bootsrap framework to a WordPress child theme

Step 1. Download latest complied bootstrap code here:

https://getbootstrap.com/docs/4.0/getting-started/download/

Step 2: Upload the Bootstrap folder to your child theme directory.

Step 3: Add the following code to your functions.php file in your child theme.

function bootstrap_enqueue_styles() {
    wp_register_style('bootstrap',get_stylesheet_directory_uri() . '/bootstrap/css/bootstrap.min.css' );
    $dependencies = array('bootstrap');
    wp_enqueue_style( 'bootstrap-style', get_stylesheet_directory_uri(), $dependencies); 
}

function bootstrap_enqueue_scripts() {
    $dependencies = array('jquery');
    wp_enqueue_script('bootstrap-script', get_stylesheet_directory_uri().'/bootstrap/js/bootstrap.min.js', $dependencies, '3.3.6', true );
}

add_action( 'wp_enqueue_scripts', 'bootstrap_enqueue_styles' ,1);
add_action( 'wp_enqueue_scripts', 'bootstrap_enqueue_scripts',1 );