Passing main methods arrays with their original names to another method

Question

So I have made a simple code, which passes two different arrays to a method, to check for Exceptions. But there is one problem - when I pass the arrays, if an exception is cached, in my Exceptions "nameof" part, it doesn't say which array was the one, what made the exception. I need to correct that. So do you have any ideas, how I can do this in my code?

public class CommonEnd
{
    public bool IsCommonEnd(int[] a, int[] b)
    {
        ValidateArray(a);
        ValidateArray(b);
        return a.First() == b.First() || a.Last() == b.Last();
    }

    private void ValidateArray(int[] array)
    {
        if (array == null)
        {
            throw new ArgumentNullException(nameof(array), "Array is NULL.");
        }

        if (array.Length == 0)
        {
            throw new ArgumentOutOfRangeException(nameof(array), "Array length can't be smaller that 1");
        }
    }
}

Answer 1

nameof(array) will always just return the string array. In order to know whether a or b went wrong, you can pass another parameter and use nameof one level higher

private void ValidateArray(string which, int[] array)
{
    if (array == null)
    {
        throw new ArgumentNullException(nameof(array), $"Array {which} is NULL.");
    }

    if (array.Length == 0)
    {
        throw new ArgumentOutOfRangeException(nameof(array), $"Array {which} length can't be smaller that 1");
    }
}

And in the calling method:

public bool IsCommonEnd(int[] a, int[] b)
{
    ValidateArray(nameof(a), a);
    ValidateArray(nameof(b), b);
    return a.First() == b.First() || a.Last() == b.Last();
}