How can a large Array be split into smaller arrays?

Given a large array how can it be split into smaller arrays with the size of开发者_JAVA百科 the smaller arrays specified as an argument of the method?

For instance, given numbers, what would Split's implementation be?

int[] numbers = new int[7845];

int[][] sectionedNumbers = numbers.Split(1000);

sectionedNumbers.Length; //outputs 8
sectionedNumbers[7].Length; //outputs 845

You can do it with an extension method:

using System;

static class Program
{
    static T[][] Split<T>(this T[] arrayIn, int length)
    {
        bool even = arrayIn.Length%length == 0;
        int totalLength = arrayIn.Length/length;
        if (!even)
            totalLength++;

        T[][] newArray = new T[totalLength][];
        for (int i = 0; i < totalLength;++i )
        {
            int allocLength = length;
            if (!even && i == totalLength - 1)
                allocLength = arrayIn.Length % length;

            newArray[i] = new T[allocLength];
            Array.Copy(arrayIn, i * length, newArray[i], 0, allocLength);
        }
        return newArray;
    }

    static void Main(string[] args)
    {
        int[] numbers = new int[8010];
        for (int i = 0; i < numbers.Length; ++i)
            numbers[i] = i;

        int[][] sectionedNumbers = numbers.Split(1000);

        Console.WriteLine("{0}", sectionedNumbers.Length);
        Console.WriteLine("{0}", sectionedNumbers[7].Length);
        Console.WriteLine("{0}", sectionedNumbers[1][0]);
        Console.WriteLine("{0}", sectionedNumbers[7][298]);
        Console.ReadKey();
    } 
}

This prints:

9
1000
1000
7298

This isn't necessarily a good idea, but here's an implementation that generalises this splitting operation to IEnumerable<T>, returning an IEnumerable<IEnumerable<T>>.

public static IEnumerable<IEnumerable<T>> Split<T>(this IEnumerable<T> input, int size)
{
    return input.Select((a, i) => new { Item = a, Index = i })
                .GroupBy( b => (b.Index / size))
                .Select(c => c.Select(d => d.Item));
}

Reed beat me to it, but here's my method anyway:

public int[][] Split(int[] source, int size)
{
    int fullArrayCount = source.Length / size;
    int totalArrayCount = fullArrayCount;
    int remainder = source.Length - (fullArrayCount * size);
    if (remainder > 0)
    {
        totalArrayCount++;
    }
    int[][] output = new int[totalArrayCount][];
    for (int i = 0; i < fullArrayCount; i++)
    {
        output[i] = new int[size];
        Array.Copy(source, i * size, output[i], 0, size);
    }
    if (totalArrayCount != fullArrayCount)
    {
        output[fullArrayCount] = new int[remainder];
        Array.Copy(source, fullArrayCount * size,
            output[fullArrayCount], 0, remainder);
    }

    return output;
}