How to Convert a byte array into an int array? I have a byte array holding 144 items and the ways I have tried are quite inefficient due to my inexperience. I am sorry if this has been answered before, but I couldn't find a good answer anywhere.
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1What are the ways you have tried?Marlon– Marlon2012-06-20 02:57:32 +00:00Commented Jun 20, 2012 at 2:57
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Just to mention - byte is 8 bit, int is 32 bit, and you are converting a byte to int. All of the converted ints will range from 0 to 255.Bakudan– Bakudan2017-07-26 20:16:59 +00:00Commented Jul 26, 2017 at 20:16
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5 Answers
Simple:
//Where yourBytes is an initialized byte array.
int[] bytesAsInts = yourBytes.Select(x => (int)x).ToArray();
Make sure you include System.Linq with a using declaration:
using System.Linq;
And if LINQ isn't your thing, you can use this instead:
int[] bytesAsInts = Array.ConvertAll(yourBytes, c => (int)c);
4 Comments
user1166981
I got an error: 'byte[]' does not contain a definition for 'Select' and no extension method 'Select' accepting a first argument of type 'byte[]' could be found (are you missing a using directive or an assembly reference?)
Ry-
@user1166981: Make sure to reference
System.Linq in your project. (Which version of the .NET framework are you targeting, by the way?)
Dai
This approach is very slow: Linq is not optimized for
byte block copies. It's much faster to do int[] bytesAsInts = new int[ yourBytes.Length / 2 ]; Buffer.BlockCopy( yourBytes, 0, bytesAsInts, 0, yourBytes.Length );.
jwalk
This is a very misleading answer. Typecasting each item of the
byte[] will not properly cast the full 4 bytes of each int. Not sure why it is accepted.I known this is an old post, but if you were looking in the first place to get an array of integers packed in a byte array (and it could be considering your array byte of 144 elements), this is a way to do it:
var size = bytes.Count() / sizeof (int);
var ints = new int[size];
for (var index = 0; index < size; index++)
{
ints[index] = BitConverter.ToInt32(bytes, index * sizeof (int));
}
Note: take care of the endianness if needed. (And in most case it will)
2 Comments
Revils
Nice, was looking for this. People seem to forget that (int)byteVar is not the same as converting a bytearray into an int (for example 4 bytes for one int)
BlueRaja - Danny Pflughoeft
There is a better solution: stackoverflow.com/a/5896716/238419 That question is about
int[] to byte[] but this solution should work regardlessUse Buffer.BlockCopy instead of Array.ConvertAll.
ref Converting an int[] to byte[] in C#
byte[] bytes = new byte[] { 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8 };
int[] ints = Array.ConvertAll(bytes, Convert.ToInt32);
will return ints[] = {0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8},
not return ints[] = {0x04030201,0x08070605}
You should use
Buffer.BlockCopy(bytes, 0, ints, 0, bytes.Length);
Comments
Now It's Simple like follows,
int[] result = Array.ConvertAll(bytesArray, Convert.ToInt32);
Comments
What you really need is:
Span<int> integerArray = MemoryMarshal.Cast<byte, int>(byteArray.AsSpan());
2 Comments
Robin Lindner
This is of course optimal from a performance point of view, but I don't think that was the questioner's intention. You are reinterpreting the byte array as an integer span. I guess the questioner wanted to have an array/span where each byte is seen as an individual integer.
Charles
This is just a cast, so if you have bytes likes 1,2,3 it will convert them into some really big integer, which might not be what you want.