Question

I would like to know an efficient method to remove duplicate items from a string array in C#.

For example,

string[] a = { "abc", "xyz","abc", "def", "ghi", "asdf", "ghi","xd", "abc" };

will become,

string[] a = { "abc", "xyz","def", "ghi", "asdf", "xd" };

How to fill the gaps after removing the duplicate entries?
Is there a way to do this without using an extra array for storing the elements?

Method which I used:

1) Sorted the array

2) Replaced the duplicate entries with null

3) Copied NOT null string to a new array.

But looking for an optimized way to doing the same.

EDIT: I am using .NET 2.0 and VS 2005

Answer 1

You can use a HashSet:

string[] a = { "abc", "xyz","abc", "def", "ghi", "asdf", "ghi","xd", "abc" };
var b = new HashSet<string>(a);