woocommerce getting session variable value direct in billing address 5bphp session 5d

1/**
2 * Getting Session Variable Value direct in Billing Address..
3 *
4 * PHP SESSION  VARIABLE
5 * 
6 * 
7 */
8
9add_filter( 'woocommerce_checkout_fields' , 'ahmadyani_checkout_field_defaults', 20 );
10function ahmadyani_checkout_field_defaults( $fields ) {
11    // $user = get_user_meta(get_current_user_id());
12    // $first_name = $user ? $user['shipping_first_name'][0] : '';
13    // $last_name = $user ? $user['shipping_last_name'][0] : '';
14    // $company = $user ? $user['shipping_company'][0] : '';
15    // $shipping_address_1 = $user ? $user['shipping_address_1'][0] : '';
16    // $shipping_address_2 = $user ? $user['shipping_address_2'][0] : '';
17    // $shipping_city = $user ? $user['shipping_city'][0] : '';
18    // $shipping_state = $user ? $user['shipping_state'][0] : '';
19    // $shipping_postcode = $user ? $user['shipping_postcode'][0] : '';
20    if($_SESSION['number'] !== 0){
21
22    $fields['billing']['store_location']['default'] = $_SESSION['number'];
23      
24    }
25    // else if($_SESSION['loc2'] !== 0){
26
27    // $fields['billing']['billing_address_2']['default'] = $_SESSION['loc2'];
28     
29    // }
30    return $fields;
31}
32