Question

Hi I was trying to find the number of elements in an array

byte[] salt = new byte[32];

now I only have mentioned size 32 so the Length Property of Array and Enumerable’s Count Method will give me 32.

Even if I will iterate on this Array salt using for or foreach or any other looping construct it will iterate 32 times and on each index the value is 0 (i.e default value of byte)

Now suppose I do:

for (int i = 0; i < 5 ; i++)
        {
            salt[i] = 4-i;
        }

And I want to know how many elements are inserted sequentially in Array starting from index 0, Here you may say are you fool you iterating it 5 times and you know the number is 5 , but I am having heavy looping and other logic (appending prepending to another arrays of byte) in it. *My question Is there any other inbuilt function that could give me this number 5 ? * Even if I iterate and check for first default value and break the loop there and get the count but there might be the chance last value inserted is 0 like above salt[4] is 0 so that iterating will give me the count 4 which is incorrect . If I am not wrong I think when we declare Array with size like 32 above 32 consecutive memory bytes are reserved and you are free to insert at any index from 0-31 and its your responsibility to keep the track where and how and how many elements are assigned to Array .I hope you got my point And thanks in advance for help.

Answer 1

An array is an array, and in .NET is initialized when it is allocated. Once it’s initialized, the question of whether a given value is uninitialized or simply 0 isn’t something that’s possible to check. A 0 is a 0.

However, you can bypass that in several ways. You can use a List<int>, like @SLaks suggested, to have a dynamically allocated list that’s only initialized with the elements you want.

You can also use, instead of an array of int, and array of int?, so a null value isn’t the same as a 0.