The community is working on translating this tutorial into Hungarian, but it seems that no one has started the translation process for this article yet. If you can help us, then please click "More info".
If you are fluent in Hungarian, then please help us - just point to any untranslated element (highlighted with a yellow left border - remember that images should have their titles translated as well!) inside the article and click the translation button to get started. Or have a look at the current translation status for the Hungarian language.
If you see a translation that you think looks wrong, then please consult the original article to make sure and then use the vote button to let us know about it.
Please help us by translating the following metadata for the article/chapter, if they are not already translated.
If you are not satisfied with the translation of a specific metadata item, you may vote it down - when it reaches a certain negative threshold, it will be removed. Please only submit an altered translation of a metadata item if you have good reasons to do so!
The NULL coalescing operator
The ?? operator is also called the "null-coalescing operator" because it allows you to check for a NULL value and assign a fallback value in one line of code. This might seem trivial to do without this operator, but consider the following example:
string userSuppliedName = null;
if (userSuppliedName == null)
Console.WriteLine("Hello," + userSuppliedName);
You should think of the variable userSuppliedName as something that comes from the user, e.g. from a dialog or a data file - something that could result in the value being NULL. We must deal with this by checking the value before using it, in this case for displaying the name to the user.
In the above example, we use the classical if-else approach, but with the null-coalescing operator, we can do it much shorter, in a single line:
Console.WriteLine("Hello, " + (userSuppliedName ?? "Anonymous"));
In a single statement, we ask the interpreter to use the userSuppliedName variable if it has a value – if not, we supply a fallback value, in this case the name "Anonymous". Short and simple!
As with all "syntactical sugar", like the null-coalescing operator, it's always a compromise between keeping the code short and readable. Some find that these operators make it harder to read and navigate the code, while others love how short and simple it is. In the end, it's all up to you!