空试验与尝试捕捉 [英] null test versus try catch

问题描述

有没有人有与在尝试捕捉封装代码进行测试空指标？

Does anyone have metrics on performing null test versus wrapping code in a try catch?

我怀疑是空的测试是更有效的，但我不。有什么经验数据

I suspect that the null test is much more efficient, but I don't have any empirical data.

环境是C＃/。NET 3.x和代码比较：

The environment is C#/.net 3.x and the code comparison is:

Dude x = (Dude)Session["xxxx"];
x = x== null ? new Dude(): x;

与

versus

Dude x = null;
try {
    x = (Dude)Session["xxxx"];
    x.something();
} catch {
    x = new Dude();
}

有什么优势，在尝试捕捉包装？

are there any advantages to wrapping in try catch?

推荐答案

如果null是一个可能的预期值，则测试空。如果你不喜欢空试验和有一个默认值，可以使用空coelescing操作员设置的默认值：

If null is a possible expected value, then test for null. If you don't like the null test and have a default value, you can use the null coelescing operator to set the default value:

// value is (Dude)Session["xxxx"] if not null, otherwise it's a new object.
Dude x = (Dude)Session["xxxx"] ?? new Dude();

保存try / catch语句的例外（真正的突发事件）。

Save try/catch for Exceptions (truly unexpected events).

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