c# convert byte array of ascii values to integer array

Question

I have a byte array of 50 bytes representing 5 integers as ascii characters values. Every integer value is represented as 10 bytes:

byte[] receiveBytes = new byte[] {
  20, 20, 20, 20, 20, 20, 20, 20, 20, 49,  // 9 spaces then '1'
  20, 20, 20, 20, 20, 20, 20, 20, 20, 50,  // 9 spaces then '2'
  20, 20, 20, 20, 20, 20, 49, 50, 51, 52,  // 6 spaces then '1' '2' '3' '4'
  20, 20, 20, 20, 20, 20, 53, 56, 48, 49,  // 6 spaces then '5' '8' '0' '1'
  20, 20, 20, 20, 20, 20, 20, 57, 57, 57}; // 7 spaces then '9' '9' '9'

Please, notice that 20 is an ascii code of space and [48..57] are ascii codes of 0..9 digits.

How can I convert the byte array to an integer array (int[] intvalues == [1, 2, 1234, 5801, 999])?

I have tried first to convert byte array to string and then string to integer like this:

string[] asciival = new string[10];
int[] intvalues = new int[5];

Byte[] receiveBytes = '20202020202020202049  //int value = 1
                       20202020202020202050  //int value = 2
                       20202020202049505152  //int value = 1234
                       20202020202053564849  //int value =5801
                       20202020202020575757';//int value = 999

asciival[0] = Encoding.ASCII.GetString(receiveBytes, 0, 10);
asciival[1] = Encoding.ASCII.GetString(receiveBytes, 10, 10);

intvalues[0] = int.Parse(asciival[0]);
intvalues[1] = int.Parse(asciival[1]);

But isn't there a simpler way to copy the byte array into the string array?

Maybe duplicated with http://stackoverflow.com/questions/6165171/convert-byte-array-to-int — GSP, Feb 09 '17 at 10:53
How do you make `int` that is 10 bytes wide ? `sizeof(int) == 4` — mrogal.ski, Feb 09 '17 at 10:55

score 1 · Answer 1 · answered Feb 09 '17 at 11:03

A for loop can simplify the writing:

byte[] recv = new byte[]{ /* ... */ }

int[] intvalues = new int[recv.Length / 10];

for(int pos = 0; pos < recv.Length; pos += 10)
    intvalues[pos / 10] = int.Parse(Encoding.ASCII.GetString(recv, pos, pos + 10));

Dmitry Bychenko · Answer 2 · 2017-02-09T11:54:20.670

I suggest using Linq:

Split initial array on 10-items (i.e. 10-byte) chunks
Filter digits ('0'..'9' ) in each chunk
Aggergate digits into a single integer

Implementation:

  using System.Linq;
  ...

  Byte[] receiveBytes = new byte[] {
    20, 20, 20, 20, 20, 20, 20, 20, 20, 49,  // 9 spaces then '1'
    20, 20, 20, 20, 20, 20, 20, 20, 20, 50,  // 9 spaces then '2'
    20, 20, 20, 20, 20, 20, 49, 50, 51, 52,  // 6 spaces then '1' '2' '3' '4'
    20, 20, 20, 20, 20, 20, 53, 56, 48, 49,  // 6 spaces then '5' '8' '0' '1'
    20, 20, 20, 20, 20, 20, 20, 57, 57, 57}; // 7 spaces then '9' '9' '9'

  int[] intvalues = Enumerable.Range(0, receiveBytes.Length / 10)
    .Select(index => receiveBytes
       .Skip(index * 10) // Skip + Take: splitting on 10-items chunks
       .Take(10)                  
       .Where(b => b >= '0' && b <= '9') // just digits 
       .Aggregate(0, (s, a) => s * 10 + a - '0')) 
    .ToArray();

Test

  Console.Write(string.Join(", ", intvalues));

Outcome:

  1, 2, 1234, 5801, 999

Please, notice, that 10 digits number can well overflow int since maximum int value (int.MaxValue) is 2147483647 only. To represent the initial byte[] as a string you can use Linq once again:

  var result = Enumerable
    .Range(0, receiveBytes.Length / 10)
    .Select(index => receiveBytes
       .Skip(index * 10) // Skip + Take: splitting on 10-items chunks
       .Take(10)
       .Select(b => b.ToString("00"))) // enforce leading "0" if necessary
    .Select(items => string.Concat(items));

  string text = string.Join(Environment.NewLine, result);

  Console.Write(text);

Outcome

20202020202020202049
20202020202020202050
20202020202049505152
20202020202053564849
20202020202020575757

To be honest, I find the OP's initial code (`Encoding.ASCII.GetString` followed by `int.Parse`) much easier to read & understand. — stakx - no longer contributing, Feb 09 '17 at 12:53
@stakx: it depends on what bytes can appear in the initial `receiveBytes` array; if digits and spaces only then I agree. If, say, it can have `160` (non-breaking space), `95` (underscope), `0` (`'\0'`) etc. as placeholders then I'd rather stick to `Where` + `Aggregate` — Dmitry Bychenko, Feb 09 '17 at 12:59

score -1 · Answer 3 · answered Feb 09 '17 at 11:02

You can try this :-

using System;
using System.Text; 
class Example
{ 
  public static void Main()
  { 
  // Define a string. 
  String original = "ASCII Encoding"; 
 // Instantiate an ASCII encoding object.
   ASCIIEncoding ascii = new ASCIIEncoding(); 
// Create an ASCII byte array.
  Byte[] bytes = ascii.GetBytes(original); 
// Display encoded bytes.
  Console.Write("Encoded bytes (in hex): ");
  foreach (var value in bytes)
    Console.Write("{0:X2} ", value);
    Console.WriteLine(); // Decode the bytes and display the resulting Unicode string. 
    String decoded = ascii.GetString(bytes);
    Console.WriteLine("Decoded string: '{0}'", decoded);
  }
}

c# convert byte array of ascii values to integer array

3 Answers3