Question

In the given code example, why do we use x.ToArray() ?
Each element x is already an array isn’t it ?

Please make me less confused 🙂

    var array1 = new int[3] { 1, 2, 3 };     //New integer array
    var array2 = new int[3] { 4, 5, 6 };     //New integer array
    var array3 = new int[3] { 7, 8, 9 };     //New integer array

    IList<int[]> list4 = new List<int[]> { array1, array2, array3 };

    var theManyList = list4.SelectMany(x => x.ToArray()).ToList();

Answer 1

You don’t need it. You can just do:

list4.SelectMany(x => x).ToList();

The reason is exactly as you stated it, the arrays are already arrays. SelectMany takes an IEnumerable<T>, so no need to add the extra operation. Why someone did that in an example, don’t know. Maybe they were trying to make it clear that you had to pass an IEnumerable?