Convert Binary number in linkedList to decimal

class Solution {
    public int getDecimalValue(ListNode head) {
        if(head==null) return 0;
        ListNode temp=head;
        int res=0;
        while(temp!=null){
            res=(res<<1)|temp.val ;
           temp=temp.next; 
        }
        return res;
        
    }
}
#Status: learnt a new way to calculate decimal