当我将变量传递给另一种形式的C＃时发生NullReferenceException

Question

So I have the following situation; I want to send a couple of variables to another form. Here is some code:

// In Form1
Form3 f3 = new Form3();
f3.SetVariables(pieces);
// In Form3
string[] items;
void SetVariables(string[] array)
{
    items = array;
}

Now this does work but if I try to use:

items[x].Length

It throws a NullReferenceException , but if I use:

String.IsNullOrEmpty(items[x]);

(I am checking to see if items[x] has a value) The above code works perfectly, with no errors. Is there a reason behind this?

Thanks!

Answer 1

String.IsNullOrEmpty will check for the variable being null in the first place. Calling items[x].Length when items[x] is null will fail because there is no object to call .Length on