什么是&QUOT的目的;从"在主叫方（在C＃）的关键字？ [英] What is the purpose of the "out" keyword at the caller (in C#)?

问题描述

在C＃函数有一个输出参数，你说清楚如下：

When a C# function has an output parameter, you make that clear as follows:

private void f(out OutputParameterClass outputParameter);

这指出参数没有进行初始化时，函数被调用。但是，调用这个函数的时候，您必须重复out关键字

This states that the parameter does not have to be initialized when the function is called. However, when calling this function, you have to repeat the out keyword:

f(out outputParameter);

我想知道这是什么好。为什么需要重复功能规范的一部分？有人知道吗？

I am wondering what this is good for. Why is it necessary to repeat part of the function specification? Does anyone know?

推荐答案

最好的答案我被张贴通过的底座：

The best answer I got was posted as a comment by plinth:

有关出来的重复最重要的原因/ REF是，如果你调用该函数获取与重构不同的签名，你会得到一个编译错误。最值得注意的是，如果一个参数非出去了的话，你马上就会知道。

The most important reason for the repeating of out/ref is that if the function you're calling gets refactored with a different signature, you will get a compile error. Most notably, if a parameter goes from non-out to out, you'll know right away.

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