程序整理后未声明的标识符？ [英] Undeclared identifiers after program tidy-up?

问题描述

我已经开始将我的代码拆分为模块，位于编译器的同一个Project文件夹中。我已经尽力解决这个问题，现在我需要一位专家！


例如，在一个.C文件中，我有一个函数clsLCD（）。这是在关联的.C文件中定义并声明为原型，并在我的definitions.h文件中声明为原型。但是，当我构建项目时，我在与另一个调用该函数的.C文件相关的表达式中获得了未声明的标识符''clsLCD''。


我被告知要使用extern重复定义，但是我必须在所有中重复所有定义其他模块，或者我可以使用单个defs.c。文件中包含这些外部定义吗？


有人可以查看这些文件并解释如何摆脱这些错误。


TIA


Nigel

I''ve started to split my code into modules, within the same Project folder in my compiler. I''ve done my best to sort this out, now I need an expert!

For example, in one of the .C files I have a function clsLCD(). This is defined and declared as a prototype in the associated .C file, plus declared as a prototype in my definitions.h file. However, when I build the project I get Undeclared identiifier ''clsLCD'' in expression relating to another .C file that calls the function.

I''ve been told to repeat the definitions using extern, but do I have to repeat all the definitions in all the other modules, or can I have a single "defs.c" file with these extern definitions in it?

Could someone have a look at these files and explain how to get rid of these errors.

TIA

Nigel

推荐答案

我问过几天的问题之前关于在不同的c文件中共享全局变量。
包括标题文件。


这可以帮助你理解外部


问候，

johny

I have asked a question several days ago about sharing a global variable in different c files.
including header file.

This can help you to understand extern

regards,
johny

你好Johny，


我想我明白extern意味着什么，但我仍然对如何解决我的问题感到困惑。

Hi Johny,

I think I understand what extern means, but I''m still confused about how to resolve my problem.

您的extern声明不应该在任何C / CPP源文件中。应该在H头文件中。然后，您可以将该头文件#include到所有C / CPP文件中，从而确保所有源文件都看到相同的声明集。

You extern declarations should not be in any C/CPP source files. The should be in a H header file. You can then #include that header file into all your C/CPP file thus ensuring all the source files see the same set of declarations.

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