c# - split string into two array on behalf of odd or even

Question

i have this array:

 string[] words = new string[] {"a","b","c","d","e","f"};

I want to split it in two arrays depending if the index is even or odd, like this:

string[] odd="a,c,e";
string [] even="b,d,f";

thanks in advance

Answer 1

You can use the overload of Enumerable.Where with the index and the remainder %:

string[] even =  words.Where((str, ix) => ix % 2 == 0).ToArray();
string[]  odd =  words.Where((str, ix) => ix % 2 == 1).ToArray();

Another way using ToLookup:

var evenOddIndexLookup = words.Select((str, index) => new { str, index }).ToLookup(x => x.index % 2);
string[] even = evenOddIndexLookup[0].Select(x => x.str).ToArray();
string[]  odd = evenOddIndexLookup[1].Select(x => x.str).ToArray();