What is difference between Array and ArrayList? When will you use
Array over ArrayList?

• Arrays can contain primitive or Objects whereas ArrayList can contain only Objects.
• Arrays are fixed size whereas ArrayList size is dynamic.
• Arrays doesn’t provide a lot of features like ArrayList, such as addAll, removeAll, iterator etc.

Although ArrayList is the obvious choice when we work on list, there are few times when array are good to use.

• If the size of list is fixed and mostly used to store and traverse them.
• For list of primitive data types, although Collections use autoboxing to reduce the coding effort but still it makes them slow when working on fixed size primitive data types.
• If you are working on fixed multi-dimensional situation, using [][] is far more easier than List<List>