arraylist

Question

hiiiiii i have some doubt plz clear me. . Q. when adding a collection to the array list we are using AddRange instead of Add. why it is? what is the need of AddRange?

Maha · Answer

http://www.dotnetperls.com/arraylist

Vulpes · Answer

There are two ways in which you can add a collection to an ArrayList: 1. You can use the Add method to add the collection object as a single element of the ArrayList. You can then access individual members of the collection in the following way: ArrayList al = new ArrayList(); int[] ia = {1 2 3}; al.Add(ia); int i = (al[0] as int[])[1]; // i == 2 2. You can use the AddRange method so that the individual elements of the collection become individual elements of the ArrayList: al.AddRange(ia); int i = (int)al[2]; // i == 3 Which you prefer will depend on whether you're trying to create a collection of collections (use Add) or a collection of some basic type such as int double etc. from existing collections of that type (use AddRange).

Sanjeeb Lenka · Answer

hi AddRange adds an entire collection of elements. It can replace tedious foreach-loops that repeatedly call Add on List . Add will add one item at a time. ex: using System; using System.Collections.Generic; class Program { static void Main() { List a = new List (); a.Add(1); a.Add(2); a.Add(5); a.Add(6); // Contains: // 1 // 2 // 5 // 6 int[] b = new int[3]; b[0] = 7; b[1] = 6; b[2] = 7; a.AddRange(b); // Contains: // 1 // 2 // 5 // 6 // 7 [added] // 6 [added] // 7 [added] foreach (int i in a) { Console.WriteLine(i); } } } Output 1 2 5 6 7 6 7