I took Matt's LINQ example one step further for code cleanliness:
byte[] rv = a1.Concat(a2).Concat(a3).ToArray();
In my case, the arrays are small, so I'm not concerned about performance.
Can use generics to combine arrays. Following code can easily be expanded to three arrays. This way you never need to duplicate code for different type of arrays. Some of the above answers seem overly complex to me.
private static T[] CombineTwoArrays<T>(T[] a1, T[] a2)
{
T[] arrayCombined = new T[a1.Length + a2.Length];
Array.Copy(a1, 0, arrayCombined, 0, a1.Length);
Array.Copy(a2, 0, arrayCombined, a1.Length, a2.Length);
return arrayCombined;
}
If you simply need a new byte array, then use the following:
byte[] Combine(byte[] a1, byte[] a2, byte[] a3)
{
byte[] ret = new byte[a1.Length + a2.Length + a3.Length];
Array.Copy(a1, 0, ret, 0, a1.Length);
Array.Copy(a2, 0, ret, a1.Length, a2.Length);
Array.Copy(a3, 0, ret, a1.Length + a2.Length, a3.Length);
return ret;
}
Alternatively, if you just need a single IEnumerable, consider using the C# 2.0 yield operator:
IEnumerable<byte> Combine(byte[] a1, byte[] a2, byte[] a3)
{
foreach (byte b in a1)
yield return b;
foreach (byte b in a2)
yield return b;
foreach (byte b in a3)
yield return b;
}
Concat is the right answer, but for some reason a handrolled thing is getting the most votes. If you like that answer, perhaps you'd like this more general solution even more:
IEnumerable<byte> Combine(params byte[][] arrays)
{
foreach (byte[] a in arrays)
foreach (byte b in a)
yield return b;
}
which would let you do things like:
byte[] c = Combine(new byte[] { 0, 1, 2 }, new byte[] { 3, 4, 5 }).ToArray();
All you need to pass list of Byte Arrays and this function will return you the Array of Bytes (Merged). This is the best solution i think :).
public static byte[] CombineMultipleByteArrays(List<byte[]> lstByteArray)
{
using (var ms = new MemoryStream())
{
using (var doc = new iTextSharp.text.Document())
{
using (var copy = new PdfSmartCopy(doc, ms))
{
doc.Open();
foreach (var p in lstByteArray)
{
using (var reader = new PdfReader(p))
{
copy.AddDocument(reader);
}
}
doc.Close();
}
}
return ms.ToArray();
}
}
The memorystream class does this job pretty nicely for me. I couldn't get the buffer class to run as fast as memorystream.
using (MemoryStream ms = new MemoryStream())
{
ms.Write(BitConverter.GetBytes(22),0,4);
ms.Write(BitConverter.GetBytes(44),0,4);
ms.ToArray();
}
Here's a generalization of the answer provided by @Jon Skeet. It is basically the same, only it is usable for any type of array, not only bytes:
public static T[] Combine<T>(T[] first, T[] second)
{
T[] ret = new T[first.Length + second.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
return ret;
}
public static T[] Combine<T>(T[] first, T[] second, T[] third)
{
T[] ret = new T[first.Length + second.Length + third.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
Buffer.BlockCopy(third, 0, ret, first.Length + second.Length,
third.Length);
return ret;
}
public static T[] Combine<T>(params T[][] arrays)
{
T[] ret = new T[arrays.Sum(x => x.Length)];
int offset = 0;
foreach (T[] data in arrays)
{
Buffer.BlockCopy(data, 0, ret, offset, data.Length);
offset += data.Length;
}
return ret;
}
Many of the answers seem to me to be ignoring the stated requirements:
These two together rule out a LINQ sequence of bytes - anything with yield is going to make it impossible to get the final size without iterating through the whole sequence.
If those aren't the real requirements of course, LINQ could be a perfectly good solution (or the IList<T> implementation). However, I'll assume that Superdumbell knows what he wants.
(EDIT: I've just had another thought. There's a big semantic difference between making a copy of the arrays and reading them lazily. Consider what happens if you change the data in one of the "source" arrays after calling the Combine (or whatever) method but before using the result - with lazy evaluation, that change will be visible. With an immediate copy, it won't. Different situations will call for different behaviour - just something to be aware of.)
Here are my proposed methods - which are very similar to those contained in some of the other answers, certainly :)
public static byte[] Combine(byte[] first, byte[] second)
{
byte[] ret = new byte[first.Length + second.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
return ret;
}
public static byte[] Combine(byte[] first, byte[] second, byte[] third)
{
byte[] ret = new byte[first.Length + second.Length + third.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
Buffer.BlockCopy(third, 0, ret, first.Length + second.Length,
third.Length);
return ret;
}
public static byte[] Combine(params byte[][] arrays)
{
byte[] ret = new byte[arrays.Sum(x => x.Length)];
int offset = 0;
foreach (byte[] data in arrays)
{
Buffer.BlockCopy(data, 0, ret, offset, data.Length);
offset += data.Length;
}
return ret;
}
Of course the "params" version requires creating an array of the byte arrays first, which introduces extra inefficiency.
I took Matt's LINQ example one step further for code cleanliness:
byte[] rv = a1.Concat(a2).Concat(a3).ToArray();
In my case, the arrays are small, so I'm not concerned about performance.
If you simply need a new byte array, then use the following:
byte[] Combine(byte[] a1, byte[] a2, byte[] a3)
{
byte[] ret = new byte[a1.Length + a2.Length + a3.Length];
Array.Copy(a1, 0, ret, 0, a1.Length);
Array.Copy(a2, 0, ret, a1.Length, a2.Length);
Array.Copy(a3, 0, ret, a1.Length + a2.Length, a3.Length);
return ret;
}
Alternatively, if you just need a single IEnumerable, consider using the C# 2.0 yield operator:
IEnumerable<byte> Combine(byte[] a1, byte[] a2, byte[] a3)
{
foreach (byte b in a1)
yield return b;
foreach (byte b in a2)
yield return b;
foreach (byte b in a3)
yield return b;
}
Concat is the right answer, but for some reason a handrolled thing is getting the most votes. If you like that answer, perhaps you'd like this more general solution even more:
IEnumerable<byte> Combine(params byte[][] arrays)
{
foreach (byte[] a in arrays)
foreach (byte b in a)
yield return b;
}
which would let you do things like:
byte[] c = Combine(new byte[] { 0, 1, 2 }, new byte[] { 3, 4, 5 }).ToArray();
Many of the answers seem to me to be ignoring the stated requirements:
These two together rule out a LINQ sequence of bytes - anything with yield is going to make it impossible to get the final size without iterating through the whole sequence.
If those aren't the real requirements of course, LINQ could be a perfectly good solution (or the IList<T> implementation). However, I'll assume that Superdumbell knows what he wants.
(EDIT: I've just had another thought. There's a big semantic difference between making a copy of the arrays and reading them lazily. Consider what happens if you change the data in one of the "source" arrays after calling the Combine (or whatever) method but before using the result - with lazy evaluation, that change will be visible. With an immediate copy, it won't. Different situations will call for different behaviour - just something to be aware of.)
Here are my proposed methods - which are very similar to those contained in some of the other answers, certainly :)
public static byte[] Combine(byte[] first, byte[] second)
{
byte[] ret = new byte[first.Length + second.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
return ret;
}
public static byte[] Combine(byte[] first, byte[] second, byte[] third)
{
byte[] ret = new byte[first.Length + second.Length + third.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
Buffer.BlockCopy(third, 0, ret, first.Length + second.Length,
third.Length);
return ret;
}
public static byte[] Combine(params byte[][] arrays)
{
byte[] ret = new byte[arrays.Sum(x => x.Length)];
int offset = 0;
foreach (byte[] data in arrays)
{
Buffer.BlockCopy(data, 0, ret, offset, data.Length);
offset += data.Length;
}
return ret;
}
Of course the "params" version requires creating an array of the byte arrays first, which introduces extra inefficiency.
If you simply need a new byte array, then use the following:
byte[] Combine(byte[] a1, byte[] a2, byte[] a3)
{
byte[] ret = new byte[a1.Length + a2.Length + a3.Length];
Array.Copy(a1, 0, ret, 0, a1.Length);
Array.Copy(a2, 0, ret, a1.Length, a2.Length);
Array.Copy(a3, 0, ret, a1.Length + a2.Length, a3.Length);
return ret;
}
Alternatively, if you just need a single IEnumerable, consider using the C# 2.0 yield operator:
IEnumerable<byte> Combine(byte[] a1, byte[] a2, byte[] a3)
{
foreach (byte b in a1)
yield return b;
foreach (byte b in a2)
yield return b;
foreach (byte b in a3)
yield return b;
}
Concat is the right answer, but for some reason a handrolled thing is getting the most votes. If you like that answer, perhaps you'd like this more general solution even more:
IEnumerable<byte> Combine(params byte[][] arrays)
{
foreach (byte[] a in arrays)
foreach (byte b in a)
yield return b;
}
which would let you do things like:
byte[] c = Combine(new byte[] { 0, 1, 2 }, new byte[] { 3, 4, 5 }).ToArray();
Many of the answers seem to me to be ignoring the stated requirements:
These two together rule out a LINQ sequence of bytes - anything with yield is going to make it impossible to get the final size without iterating through the whole sequence.
If those aren't the real requirements of course, LINQ could be a perfectly good solution (or the IList<T> implementation). However, I'll assume that Superdumbell knows what he wants.
(EDIT: I've just had another thought. There's a big semantic difference between making a copy of the arrays and reading them lazily. Consider what happens if you change the data in one of the "source" arrays after calling the Combine (or whatever) method but before using the result - with lazy evaluation, that change will be visible. With an immediate copy, it won't. Different situations will call for different behaviour - just something to be aware of.)
Here are my proposed methods - which are very similar to those contained in some of the other answers, certainly :)
public static byte[] Combine(byte[] first, byte[] second)
{
byte[] ret = new byte[first.Length + second.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
return ret;
}
public static byte[] Combine(byte[] first, byte[] second, byte[] third)
{
byte[] ret = new byte[first.Length + second.Length + third.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
Buffer.BlockCopy(third, 0, ret, first.Length + second.Length,
third.Length);
return ret;
}
public static byte[] Combine(params byte[][] arrays)
{
byte[] ret = new byte[arrays.Sum(x => x.Length)];
int offset = 0;
foreach (byte[] data in arrays)
{
Buffer.BlockCopy(data, 0, ret, offset, data.Length);
offset += data.Length;
}
return ret;
}
Of course the "params" version requires creating an array of the byte arrays first, which introduces extra inefficiency.
All you need to pass list of Byte Arrays and this function will return you the Array of Bytes (Merged). This is the best solution i think :).
public static byte[] CombineMultipleByteArrays(List<byte[]> lstByteArray)
{
using (var ms = new MemoryStream())
{
using (var doc = new iTextSharp.text.Document())
{
using (var copy = new PdfSmartCopy(doc, ms))
{
doc.Open();
foreach (var p in lstByteArray)
{
using (var reader = new PdfReader(p))
{
copy.AddDocument(reader);
}
}
doc.Close();
}
}
return ms.ToArray();
}
}
Can use generics to combine arrays. Following code can easily be expanded to three arrays. This way you never need to duplicate code for different type of arrays. Some of the above answers seem overly complex to me.
private static T[] CombineTwoArrays<T>(T[] a1, T[] a2)
{
T[] arrayCombined = new T[a1.Length + a2.Length];
Array.Copy(a1, 0, arrayCombined, 0, a1.Length);
Array.Copy(a2, 0, arrayCombined, a1.Length, a2.Length);
return arrayCombined;
}
/// <summary>
/// Combine two Arrays with offset and count
/// </summary>
/// <param name="src1"></param>
/// <param name="offset1"></param>
/// <param name="count1"></param>
/// <param name="src2"></param>
/// <param name="offset2"></param>
/// <param name="count2"></param>
/// <returns></returns>
public static T[] Combine<T>(this T[] src1, int offset1, int count1, T[] src2, int offset2, int count2)
=> Enumerable.Range(0, count1 + count2).Select(a => (a < count1) ? src1[offset1 + a] : src2[offset2 + a - count1]).ToArray();
Here's a generalization of the answer provided by @Jon Skeet. It is basically the same, only it is usable for any type of array, not only bytes:
public static T[] Combine<T>(T[] first, T[] second)
{
T[] ret = new T[first.Length + second.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
return ret;
}
public static T[] Combine<T>(T[] first, T[] second, T[] third)
{
T[] ret = new T[first.Length + second.Length + third.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
Buffer.BlockCopy(third, 0, ret, first.Length + second.Length,
third.Length);
return ret;
}
public static T[] Combine<T>(params T[][] arrays)
{
T[] ret = new T[arrays.Sum(x => x.Length)];
int offset = 0;
foreach (T[] data in arrays)
{
Buffer.BlockCopy(data, 0, ret, offset, data.Length);
offset += data.Length;
}
return ret;
}
The memorystream class does this job pretty nicely for me. I couldn't get the buffer class to run as fast as memorystream.
using (MemoryStream ms = new MemoryStream())
{
ms.Write(BitConverter.GetBytes(22),0,4);
ms.Write(BitConverter.GetBytes(44),0,4);
ms.ToArray();
}
Concat is the right answer, but for some reason a handrolled thing is getting the most votes. If you like that answer, perhaps you'd like this more general solution even more:
IEnumerable<byte> Combine(params byte[][] arrays)
{
foreach (byte[] a in arrays)
foreach (byte b in a)
yield return b;
}
which would let you do things like:
byte[] c = Combine(new byte[] { 0, 1, 2 }, new byte[] { 3, 4, 5 }).ToArray();
I actually ran into some issues with using Concat... (with arrays in the 10-million, it actually crashed).
I found the following to be simple, easy and works well enough without crashing on me, and it works for ANY number of arrays (not just three) (It uses LINQ):
public static byte[] ConcatByteArrays(params byte[][] arrays)
{
return arrays.SelectMany(x => x).ToArray();
}
Many of the answers seem to me to be ignoring the stated requirements:
These two together rule out a LINQ sequence of bytes - anything with yield is going to make it impossible to get the final size without iterating through the whole sequence.
If those aren't the real requirements of course, LINQ could be a perfectly good solution (or the IList<T> implementation). However, I'll assume that Superdumbell knows what he wants.
(EDIT: I've just had another thought. There's a big semantic difference between making a copy of the arrays and reading them lazily. Consider what happens if you change the data in one of the "source" arrays after calling the Combine (or whatever) method but before using the result - with lazy evaluation, that change will be visible. With an immediate copy, it won't. Different situations will call for different behaviour - just something to be aware of.)
Here are my proposed methods - which are very similar to those contained in some of the other answers, certainly :)
public static byte[] Combine(byte[] first, byte[] second)
{
byte[] ret = new byte[first.Length + second.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
return ret;
}
public static byte[] Combine(byte[] first, byte[] second, byte[] third)
{
byte[] ret = new byte[first.Length + second.Length + third.Length];
Buffer.BlockCopy(first, 0, ret, 0, first.Length);
Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
Buffer.BlockCopy(third, 0, ret, first.Length + second.Length,
third.Length);
return ret;
}
public static byte[] Combine(params byte[][] arrays)
{
byte[] ret = new byte[arrays.Sum(x => x.Length)];
int offset = 0;
foreach (byte[] data in arrays)
{
Buffer.BlockCopy(data, 0, ret, offset, data.Length);
offset += data.Length;
}
return ret;
}
Of course the "params" version requires creating an array of the byte arrays first, which introduces extra inefficiency.
public static byte[] Concat(params byte[][] arrays) {
using (var mem = new MemoryStream(arrays.Sum(a => a.Length))) {
foreach (var array in arrays) {
mem.Write(array, 0, array.Length);
}
return mem.ToArray();
}
}
/// <summary>
/// Combine two Arrays with offset and count
/// </summary>
/// <param name="src1"></param>
/// <param name="offset1"></param>
/// <param name="count1"></param>
/// <param name="src2"></param>
/// <param name="offset2"></param>
/// <param name="count2"></param>
/// <returns></returns>
public static T[] Combine<T>(this T[] src1, int offset1, int count1, T[] src2, int offset2, int count2)
=> Enumerable.Range(0, count1 + count2).Select(a => (a < count1) ? src1[offset1 + a] : src2[offset2 + a - count1]).ToArray();
I actually ran into some issues with using Concat... (with arrays in the 10-million, it actually crashed).
I found the following to be simple, easy and works well enough without crashing on me, and it works for ANY number of arrays (not just three) (It uses LINQ):
public static byte[] ConcatByteArrays(params byte[][] arrays)
{
return arrays.SelectMany(x => x).ToArray();
}
public static bool MyConcat<T>(ref T[] base_arr, ref T[] add_arr)
{
try
{
int base_size = base_arr.Length;
int size_T = System.Runtime.InteropServices.Marshal.SizeOf(base_arr[0]);
Array.Resize(ref base_arr, base_size + add_arr.Length);
Buffer.BlockCopy(add_arr, 0, base_arr, base_size * size_T, add_arr.Length * size_T);
}
catch (IndexOutOfRangeException ioor)
{
MessageBox.Show(ioor.Message);
return false;
}
return true;
}
If you simply need a new byte array, then use the following:
byte[] Combine(byte[] a1, byte[] a2, byte[] a3)
{
byte[] ret = new byte[a1.Length + a2.Length + a3.Length];
Array.Copy(a1, 0, ret, 0, a1.Length);
Array.Copy(a2, 0, ret, a1.Length, a2.Length);
Array.Copy(a3, 0, ret, a1.Length + a2.Length, a3.Length);
return ret;
}
Alternatively, if you just need a single IEnumerable, consider using the C# 2.0 yield operator:
IEnumerable<byte> Combine(byte[] a1, byte[] a2, byte[] a3)
{
foreach (byte b in a1)
yield return b;
foreach (byte b in a2)
yield return b;
foreach (byte b in a3)
yield return b;
}
public static byte[] Concat(params byte[][] arrays) {
using (var mem = new MemoryStream(arrays.Sum(a => a.Length))) {
foreach (var array in arrays) {
mem.Write(array, 0, array.Length);
}
return mem.ToArray();
}
}
Source: Stackoverflow.com