重复符号错误C ++ [英] duplicate symbol error C++

问题描述

我在我的文件添加了一些const字符如下。我得到的错误是重复的符号_xyz（说）。它是什么问题，我怎么能摆脱这一点。

I have added some const character in my file as under. The error i get is duplicate symbol _xyz(say). What is the problem with it and how could i get out of this.

const char* xyz = "xyz";
class Abc
{
public:
    Abc()
    {
    }
};

推荐答案

如果这是一个头文件，每次 #include 时定义 xyz 。

If this is in a header file, you're defining xyz every time you #include it.

你可以改变声明为@R塞缪尔·克拉奇科显示。通常的方式（如果数据不是 const ）是这样的：

You can change the declaration as @R Samuel Klatchko shows. The usual way (if the data isn't const) is like this:

在Abc.h： / p>

In Abc.h:

extern char *xyz;

在Abc.cpp中：

char *xyz = "xyz";

已编辑以添加。

请注意，标题防护将不解决此问题：

Note that header guards will not solve this problem:

#ifndef XYZ_H
#define XYZ_H
...
#endif

redefinition错误，其中相同的符号在同一编译单元中出现两次。这是一个编译器错误。

Header guards prevent "redefinition" errors, where the same symbol appears twice in the same compilation unit. That's a compiler error.

但是，即使使用标题保护， xyz 仍会出现在包含它的每个源文件中，从而导致重复符号错误，这是一个链接器错误。

But even with header guards the definition of xyz will still appear in every source file that includes it, causing a "duplicate symbol" error, which is a linker error.

如果原来的海报提到，更有帮助，当然。

It would have been more helpful if the original poster had mentioned that, of course.

这篇关于重复符号错误C ++的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！