Get values from methods in objects that are in arraylist?

Question

ArrayList<Customer> customerList = new ArrayList<Customer>();
// add object to arraylist
customerList.add(customer);

// get objects from arraylist
customerlist.get(0);

But how do I get the value from a method that is inside the class like if I have a method like getCustomerName() inside and I want the name in return or perhaps I want to change or add something to a method. How do I write the call? Preciate some help! Thanks!

Answer 1

// Single reference.
customerlist.get(0).getCustomerName();

// Or...
Customer c = customerlist.get(0);
c.getCustomerName();

// Or looping.
for (Customer c : customerList) {
    c.getCustomerName();
}

Once you have a reference to the Customer object you can do whatever things you normally do to customers.

Answer 2

you can implement that using Map

as you have to locate some certain object using the id

map.get(id).setBalance(map.get(id).getBalance() + 100000);