c# - 检查 NameValueCollection 是否有值(value)的最优雅的方法

Question

我有一行简单的代码:lead.InternalCompany = nvCollection["ic"];

我想将 lead.InternalCompany 设置为检索到的值，但如果没有空字符串 ""

我尝试使用 nvCollection["ic"].HasValue();

我知道我可以做这样简单的事情

string value = nvCollection["ic"];
if (value == null) // key doesn't exist
    {
        lead.InternalCompany = "";
    }

理想情况下，我希望使用三元 if 语句 来完成此操作

Answer 1

使用 null-coalescing operator

The ?? operator is called the null-coalescing operator and is used to define a default value for nullable value types or reference types. It returns the left-hand operand if the operand is not null; otherwise it returns the right operand.

lead.InternalCompany = nvCollection["ic"] ?? string.Empty;