我有一个存储在列表中的常规客户超类,然后我需要能够将超类对象更改为另一个子类,甚至在子类之间(例如:银到金)。我尝试了这种方法,但是不起作用:
// changeMembershipID是用户输入。
for (Customer item : customersList){
changeByID = item.getCustomerID();
if (changeByID == changeMembershipID){
if(item instanceof Customer){
item = new SilverCustomer();
System.out.println("Customer with ID <" + changeMembershipID + "> has upgraded from Regular to Silver.");
}