Check out example codes for "c# add 2 arrays". It will help you in understanding the concepts better.

Code Example 1

T[] array1 = getOneArray();
T[] array2 = getAnotherArray();
T[] newArray = new T[array1.Length + array2.Length];
Array.Copy(array1, newArray, array1.Length);
Array.Copy(array2, 0, newArray, array1.Length, array2.Length);

Code Example 2

public static int[] AddArrays(int[] a, int[] b)
{
    int[] newArray = new int[a.Length];
    for (int i = 0; i<a.Length; i++)
    {
        newArray[i]=a[i]+b[i];
    }
    return newArray;
}

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