WordPress at a glance
action is not described

woocommerce_checkout_init action-hook . WC 1.0

woocommerce_checkout_init action is ran once when the class is first constructed.

Usage

add_action( 'woocommerce_checkout_init', 'action_function_name_9515' );
function action_function_name_9515( $self::$instance ){
	// action...
}
$self::$instance
-

Where the hook is called

WC_Checkout::instance()
woocommerce_checkout_init
woocommerce/includes/class-wc-checkout.php 62
do_action( 'woocommerce_checkout_init', self::$instance );

Where in WP core the hook is used WooCommerce

Usage not found.