How to check if a char array element is empty?

Question

I have on very simple array in C#:

char[] niz = new char[16];
niz[0] = 'c';
niz[1] = 's';
niz[2] = 'h';
niz[3] = 'a';
niz[4] = 'r';
niz[5] = 'p';

How can I check which element of this array is empty?

I've tried this code:

if (niz[6] == null) Console.WriteLine("6th is empty");

But in this case it's not empty, and I don't know why.

Can you help me with this please?

Answer 1

You need to use nullable types. change this to

char?[] niz = new char?[16];

then your code will work

if (!niz[6].HasValue) 
  Console.WriteLine("6th is empty");

Answer 2

Array will be initialized with default values of array element type. Char is not a reference type, so null is not default value for it. For char default is 0 .

You can check array[i] == default(char) , but this will not tell you if array item is empty, or it has default value assigned by you:

char[] niz = new char[16];
niz[0] = 'c';
niz[1] = (char)0; // default value
niz[2] = '\0'; // default value
niz[3] = 'a';
niz[4] = 'r';
niz[5] = 'p';

for(int i = 0; i < niz.Length; i++)
    Console.WriteLine(niz[i] == default(char));

As Ehsan suggested, you can use array of nullable chars, but again, you will not know whether item is not initialized, or you have assigned null value to it. I suggest you to use List<T> class instead of array. It will contain only items you need (ie no default empty items).

Answer 3

Because you are using chars, you need to say:

if (niz[6] == '\\0') Console.WriteLine("6th is empty");

Chars cannot be equal to null.

Answer 4

The problem is that char will be initialized with a default value. You need to make it nullable like this:

char?[] niz = new char?[16];

Answer 5

 char[] niz = new char[16];
        niz[0] = 'c';
        niz[1] = 's';
        niz[2] = 'h';
        niz[3] = 'a';
        niz[4] = 'r';
        niz[5] = 'p';
        for (int i = 0; i < niz.Length; i++)
        {
            if (niz[i] == '\0') Console.WriteLine(i);
        }