Subset of Array in C#

Question

If I have an array with 12 elements and I want a new array with that drops the first and 12th elements. For example, if my array looks like this:

__ __ __ __ __ __ __ __ __ __ __ __ a  b  c  d  e  f  g  h  i  j  k  l __ __ __ __ __ __ __ __ __ __ __ __ 

I want to either transform it or create a new array that looks like

__ __ __ __ __ __ __ __ __ __  b  c  d  e  f  g  h  i  j  k  __ __ __ __ __ __ __ __ __ __ 

I know I can do it by iterating over them. I was just wondering if there was a cleaner way built into C#.

**UPDATED TO FIX A TYPO. Changed 10 elements to 12 elements.

Answer 1

LINQ is your friend. :)

var newArray = oldArray.Skip(1).Take(oldArray.Length - 2).ToArray(); 

Somewhat less efficient than manually creating the array and iterating over it of course, but far simple...

The slightly lengithier method that uses Array.Copy is the following.

var newArray = new int[oldArray.Count - 2]; Array.Copy(oldArray, 1, newArray, 0, newArray.Length); 

Answer 2

Linq is all nice and snazzy, but if you're looking for a 1-liner you could just throw together your own utility functions:

static class ArrayUtilities {     // create a subset from a range of indices     public static T[] RangeSubset<T>(this T[] array, int startIndex, int length)     {         T[] subset = new T[length];         Array.Copy(array, startIndex, subset, 0, length);         return subset;     }      // create a subset from a specific list of indices     public static T[] Subset<T>(this T[] array, params int[] indices)     {         T[] subset = new T[indices.Length];         for (int i = 0; i < indices.Length; i++)         {             subset[i] = array[indices[i]];         }         return subset;     } } 

So then you could do the following:

        char[] original = new char[] { 'a', 'b', 'c', 'd', 'e', 'f', 'g' };          // array containing 'b' - 'f'         char[] rangeSubset = original.RangeSubset(1, original.Length - 2);          // array containing 'c', 'd', and 'f'         char[] specificSubset = original.Subset(2, 3, 5);