C＃如果空，则空EX pression [英] C# if-null-then-null expression

问题描述

只是出于好奇/便利：C＃提供了两个爽条件前pression功能我知道的：

Just for curiosity/convenience: C# provides two cool conditional expression features I know of:

string trimmed = (input == null) ? null : input.Trim();

和

string trimmed = (input ?? "").Trim();

我错过这样的EX pression的情况下，我面临着非常频繁：

I miss another such expression for a situation I face very often:

如果输入参考为空，则输出为空。否则，输出应该是访问输入对象的方法或属性的结果。

我所做的正是，在我的第一个例子，但（输入== NULL）？空：input.Trim（）相当冗长且无法读取

I have done exactly that in my first example, but (input == null) ? null : input.Trim() is quite verbose and unreadable.

有另一种条件EX pression这种情况下，还是可以使用 ?? 操作符优雅？

Is there another conditional expression for this case, or can I use the ?? operator elegantly?

推荐答案

喜欢的东西Groovy的空安全的对其操作？

Something like Groovy's null-safe dereferencing operator?

string zipCode = customer?.Address?.ZipCode;

据我了解，在C＃团队已经看了这一点，并发现它不是那么简单，设计优雅正如人们所预料......虽然我没有听说过的问题的细节。

I gather that the C# team has looked at this and found that it's not as simple to design elegantly as one might expect... although I haven't heard about the details of the problems.

我不相信有任何这样的事情，在语言的那一刻，我怕......我还没有听说过什么打算呢，虽然这并不是说就不会发生在一些点。

I don't believe there's any such thing in the language at the moment, I'm afraid... and I haven't heard of any plans for it, although that's not to say it won't happen at some point.

编辑：它现在将会是C＃6部分，为空条件运算符

It's now going to be part of C# 6, as the "null-conditional operator".

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