Java: List Interface and ArrayList

ArrayList allows duplicate elements and maintains insertion order.

In Java, an ArrayList can contain duplicate elements, meaning you can add the same value multiple times. This is useful in scenarios like a shopping cart in an e-commerce application, where a user can add multiple quantities of the same product. The ArrayList maintains the order in which elements are added, so duplicates will appear in the order they were inserted. For example, if you add 'apple', 'banana', and then 'apple' again, the list will contain ['apple', 'banana', 'apple'].