If adding the new element causes the count to exceed the capacity, the capacity is automatically doubled and the array is redimensioned. When adding an element thought the Add() method, the number of elements in the internal array is checked with the array's capacity. By default, an ArrayList creates a 16-element object array, although the precise size can be specified through a parameter in the constructor or the Capacity property. A generic type is a special type in C that defines a generalized class and the user specifies the data types it uses when created. The ArrayList is deprecated in support for the generic List Generic List. But it comes from a time where C didn't have generic support. The ArrayList class included in the System. An ArrayList can be used to add unknown data where you don't know the types and the size of the data. It is the same as Array except that its size increases dynamically. Since all types are derived either directly or indirectly from object, an object array can hold elements of any type. It's common to see people move to ArrayList from arrays. In C, the ArrayList is a non-generic collection of objects whose size increases dynamically. Array elements can be directly accessed.Д«ehind the scenes the ArrayList uses a System.Array of type object.All of the elements of an array must be of the same type hence arrays are referred to as homogeneous data structures.The contents of an array are stored in contiguous memory.Arrays in any programming language all share a few common properties: Below are two exerpts from the article to help answer your question:ДЄrrays are one of the simplest and most widely used data structures in computer programs. (VS.71).aspx There is also a 2.0 version which uses the List. A colon on the left side of an index means everything before, but not including, the index. List on the other hand is represented by since there are no immutable collections equivalents available in Java.The answer to your question and information on other common structures can be found here. On the jvm level, Array is represented by arrays. It's also extended by to be used when a collection that allows for item modification is needed. Moreover Array is mutable whereas List is not.ДЇurthermore is an interface implemented among others by. The major difference from usage side is that Arrays have a fixed size while (Mutable)List can adjust their size dynamically. Implements all optional list operations, and permits all elements, including null. Lists and other collections cannot be used in annotations.ДЄs to the usage, good practice is to prefer using lists over arrays everywhere except for performance critical parts of your code, the reasoning is the same to that for Java. Resizable-array implementation of the List interface. Arrays are also mapped, but they have other rules of Java interoperability.Д¬ertain array types are used in annotations (primitive arrays, Array, and arrays with enum class entries), and there's a special array literal syntax for annotations. List and MutableList are mapped types and have special behaviour in Java interoperability (Java's List is seen from Kotlin as either List or MutableList). Lists in general do not have implementations optimized for primitives, though some libraries (outside JDK) provide primitive-optimized lists. which are mapped to Java primitive arrays ( int, double, char), not boxed ones ( Array is mapped to Java's Integer). val a: Array = Array(0) // won't compileДЄrrays are optimized for primitives: there are separate IntArray, DoubleArray, CharArray etc. Println(a.size) // will always be 3 for this arrayДЄrray is invariant on T ( Array is not Array), the same for MutableList, but List is covariant ( List is List). As to the lists, MutableList has add and remove functions, so that it can increase and reduce its size. val a = arrayOf(1, 2, 3)ДЄrrays have fixed size and cannot expand or shrink retaining identity (you need to copy an array to resize it). val list1: List = LinkedList()ДЄrray is mutable (it can be changed through any reference to it), but List doesn't have modifying methods (it is either read-only view of MutableList or an immutable list implementation). indexing in a LinkedList goes through the links and takes O(n) time whereas ArrayList stores its items in a dynamically allocated array. Memory representation and operations logic of lists are defined in concrete implementation, e.g. List and MutableList are interfaces which have different implementations: ArrayList, LinkedList etc. Arrays and lists (represented by List and its subtype MutableList) have many differences, here are the most significant ones:ДЄrray is a class with known implementation: it's a sequential fixed-size memory region storing the items (and on JVM it is represented by Java array).

Array vs arraylist side by side