Difference between an Array and ArrayList

Posted by Techie Cocktail | 2:10 PM | | 1 comments »

Below are some differences.

a. The Array size needs to be defined or must have an Array Initializer at the time
of declaration. Their size remains fixed once defined and created.

string[] strArray = new string[10];
string[] strArray = { "one", "two", "three" };

b. The Array class can be found in System namespace.
c. An Array can hold similar types.
d. Arrays can be multi-dimensional.
e. Arrays are strongly typed to a type of which they are declared. For e.g string[], char[].
f. Array do not have boxing/unboxing overhead.

a. Arraylist does not requires to define its size at the time of declaration. Its size
increases or decreases dynamically as you add/remove elements from the arraylist.

ArrayList arrLst = new ArrayList();

b. The Arraylist class can be found in System.Collections namespace.
c. Arraylist does not have any restrictions on the types of objects that can be added.
d. An Arraylist is a single dimension collection.
e. Arraylist is not strongly typed to a single type, it can contain any types.
f. Arraylist have the overhead of boxing/unboxing while adding/retriving values from it.


  1. Anonymous // May 19, 2009 at 6:59 AM  

    The concept is explained very clearly.Thank u :-)