I'm currently reading a file and wanted to be able to convert the array of bytes obtained from the file into a short array.
How would I go about doing this?
+6
A:
One possibility is using Enumerable.Select:
byte[] bytes;
var shorts = bytes.Select(b => (short)b).ToArray();
Another is to use Array.ConvertAll:
byte[] bytes;
var shorts = Array.ConvertAll(bytes, b => (short)b);
Jason
2009-07-09 15:25:38
Your original suggestion (before you added the second one later on) is rather inefficient
Philippe Leybaert
2009-07-09 15:35:23
Another option would be bytes.Cast<short>().ToArray();
Joel Mueller
2009-08-09 04:04:45
Actually, this results in a InvalidCastException. The short explanation is that this code implicitly causes an boxed byte to be unboxed to a short which is not a valid unboxing operation. For details, see http://stackoverflow.com/questions/445471/puzzling-enumerable-cast-invalidcastexception.
Jason
2009-08-19 06:56:06
A:
short[] wordArray = Array.ConvertAll(byteArray, (b) => (short)b);
Philippe Leybaert
2009-07-09 15:26:06
A:
byte[] bytes;
var shorts = bytes.Select(n => System.Convert.ToInt16(n)).ToArray();
Muad'Dib
2009-07-09 15:28:13
That's extremely inefficient: Calling convert.ToInt16() for every element, storing it in a temporary list, and then copying it to an new array.
Philippe Leybaert
2009-07-09 15:30:41
yes, it is inefficient. I'm thinking that it's safer, tho, then casting.
Muad'Dib
2009-07-09 16:09:05
Safer than casting? A cast of byte to short always works. It can never throw an exception
Philippe Leybaert
2009-07-09 16:24:03
+1
A:
Hey, a short is compound of two bytes, if he's writting to the file all the shorts as true shorts, those conversions are wrong.. you must use two bytes to get the true short value, using something like
short s = (short)(bytes[0] | (bytes[1] >> 8))
This doesn't work. You have to do it like this to make it work: short s = (short)((bytes[0] << 8) | bytes[1]);
DaveN59
2009-12-03 21:12:53
A:
use Buffer.BlockCopy create the short array at half size of byte array, then copy byte data in, the fastest method by far: short[] sdata = new short[dataLen / 2]; Buffer.BlockCopy(data, x, sdata, 0, dataLen);
steppenwolfe
2010-10-30 18:27:10