检查null并分配另一个值的最短方法 [英] Shortest way to check for null and assign another value if not

问题描述

我要从数据库中提取 varchar 值，并希望将 string 设置为如果为 null ，则为。我目前正在这样做：

I am pulling varchar values out of a DB and want to set the string I am assigning them to as "" if they are null. I'm currently doing it like this:

if (string.IsNullOrEmpty(planRec.approved_by) == true)
  this.approved_by = "";
else
  this.approved_by = planRec.approved_by.toString();

似乎应该有一种方法可以像这样：

There seems like there should be a way to do this in a single line something like:

this.approved_by = "" || planRec.approved_by.toString();

但是我找不到最佳的方法。有更好的方法还是我有最好的方法？

However I can't find an optimal way to do this. Is there a better way or is what I have the best way to do it?

推荐答案

尝试一下：

this.approved_by = IsNullOrEmpty(planRec.approved_by) ? "" : planRec.approved_by.toString();

您也可以使用null-coalescing运算符，因为没有人举过例子适用于您的代码的代码是一个：

You can also use the null-coalescing operator as other have said - since no one has given an example that works with your code here is one:

this.approved_by = planRec.approved_by ?? planRec.approved_by.toString();

但该示例仅适用于 this.approved_by 与您希望将其设置为的潜在值之一相同。对于所有其他情况，您将需要使用我在第一个示例中显示的条件运算符。

But this example only works since a possible value for this.approved_by is the same as one of the potential values that you wish to set it to. For all other cases you will need to use the conditional operator as I showed in my first example.

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