In C# how can I truncate a byte[] array

Question

I have a byte[] array of one size, and I would like to truncate it into a smaller array?

I just want to chop the end off.

Answer 1

By the way, Array.Resize method takes much more time to complete. In my simple case, I just needed to resize array of bytes (~8000 items to ~20 items):

1. Array.Resize // 1728 ticks
2. Array.Copy // 8 ticks

Answer 2

You can't truncate an array in C#. They are fixed in length.

If you want a data structure that you can truncate and acts like an array, you should use List<T>. You can use the List<T>.RemoveRange method to achieve this.

Answer 3

You could use Array.Resize, but all this really does is make a truncated copy of the original array and then replaces the original array with the new one.

Answer 4

Arrays are fixed-size in C# (.NET).

You'll have to copy the contents to a new one.

byte[] sourceArray = ...
byte[] truncArray = new byte[10];

Array.Copy(sourceArray , truncArray , truncArray.Length);

Answer 5

    private static void Truncate() {

        byte[] longArray = new byte[] {1,2,3,4,5,6,7,8,9,10};

        Array.Resize(ref longArray, 5);//longArray = {1,2,3,4,5}

        //if you like linq
        byte[] shortArray = longArray.Take(5).ToArray();

    }

Answer 6

I usually create an extension method:

 public static byte[] SubByteArray(this byte[] byteArray, int len)
    {
        byte[] tmp = new byte[len];
        Array.Copy(byteArray, tmp, len);

        return tmp;
    }

Which can be called on the byte array easily like this:

buffer.SubByteArray(len)