How are items containing data in an array that is only partly filled to be tracked when the array is only partially populated?

Main difference between an array and an ArrayList is that an ArrayList can store more data types an ArrayList can store more elements an ArrayList executes faster for retrieval and insertion an ArrayList takes care of the memory management automatically an ArrayList uses positions and an array uses indices

What is an array? What is it useful for?

Java programming To use Binary search algorithm on an array, the array must be:

In what situations is it helpful to have data stored in an array with several dimensions?