woocommerce_credit_card_form_fields │ filter-hook │ WC 1.0

Usage

add_filter( 'woocommerce_credit_card_form_fields', 'wp_kama_woocommerce_credit_card_form_fields_filter', 10, 2 );

/**
 * Function for `woocommerce_credit_card_form_fields` filter-hook.
 * 
 * @param  $default_fields 
 * @param  $id             
 *
 * @return 
 */
function wp_kama_woocommerce_credit_card_form_fields_filter( $default_fields, $id ){

	// filter...
	return $default_fields;
}

$default_fields

-

$id

-

Where the hook is called

$fields = wp_parse_args( $fields, apply_filters( 'woocommerce_credit_card_form_fields', $default_fields, $this->id ) );

Where the hook is used in WooCommerce