Best way to randomize an array with .NET

Question

What is the best way to randomize an array of strings with .NET? My array contains about 500 strings and I\'d like to create a new Array with the same strings b

Answer 1

This algorithm is simple but not efficient, O(N²). All the "order by" algorithms are typically O(N log N). It probably doesn't make a difference below hundreds of thousands of elements but it would for large lists.

var stringlist = ... // add your values to stringlist

var r = new Random();

var res = new List(stringlist.Count);

while (stringlist.Count >0)
{
   var i = r.Next(stringlist.Count);
   res.Add(stringlist[i]);
   stringlist.RemoveAt(i);
}

The reason why it's O(N²) is subtle: List.RemoveAt() is a O(N) operation unless you remove in order from the end.