We use an iterator to iterate over ArrayList. We use for loop or for each loop to iterate over an array. It automatically converts primitive type to object.

We cannot store primitive type in ArrayList. The resize operation in ArrayList slows down the performance.ДЄn array can store both objects and primitives type. It performs fast in comparison to ArrayList because of fixed size.ДЄrrayList is internally backed by the array in Java. We can create an instance of ArrayList without specifying its size. It is mandatory to provide the size of an array while initializing it directly or indirectly. It contains popular classes like Vector, HashTable, and HashMap.ДЄn array is a fixed-length data structure.ДЄrrayList is a variable-length data structure.

The ArrayList is a class of Java Collections framework. It serves as a container that holds the constant number of values of the same type. The following table describes the key differences between array and ArrayList: BasisДЄn array is a dynamically-created object. They do not preserve the order of elements.Array and ArrayList both can store null values.Array and ArrayList both are used for storing elements.ArrayList arrayObj=new ArrayList()//object of ArrayListДЄrrayObj(new Integer(12)) //converts integer primitive to Integer object and added to ArrayList object

Java array vs arraylist efficiency