如何在函数内声明全局变量？

I have problem creating global variable inside function, this is simple example:

我在函数内部创建全局变量时遇到问题，这是一个简单的例子：

int main{
   int global_variable;  //how to make that
}

This is exactly what I want to do:

这正是我想要做的：

int global_variable;
int main{
                   // but I wish to initialize global variable in main function
}

4 个解决方案

#1

You have two problems:

你有两个问题：

main is not a loop. It's a function.

主要不是循环。这是一个功能。
Your function syntax is wrong. You need to have parentheses after the function name. Either of these are valid syntaxes for main:

你的函数语法错了。您需要在函数名后面加括号。这些都是main的有效语法：
```
int main() {
}

int main(int argv, const char* argv[]) {
}
```

Then, you can declare a local variable inside main like so:

然后，您可以在main中声明一个局部变量，如下所示：

int main() {
  int local_variable = 0;
}

or assign to a global variable like so:

或者像这样分配一个全局变量：

int global_variable;

int main() {
  global_variable = 0;
}

#2

There is no way to declare it the way you want. And that's it.

没有办法按照你想要的方式声明它。就是这样。

But:

但：

First, if you want you can declare it before the main body but assign a value to it inside main. Look Paul's answer for that
首先，如果你想要你可以在主体之前声明它，但在main中为它分配一个值。看看保罗对此的回答
Second, actually there is no advantage of declaring variables the way you want. They are global and that means they should be declared in the global scope and no other places.
其次，实际上没有以你想要的方式声明变量的优势。它们是全球性的，这意味着它们应该在全球范围内宣布，而不是其他地方。

#3

int global_variable;
int main()
{
               global_variable=3; // look you assigned your value.
}

#4

well... its indirectly possible by declaring pointers global, and later assigning local variables to them, but sometimes it may lead to situations where pointed variable is unaccessible .

好吧...通过将指针声明为全局，然后将局部变量分配给它们可以间接实现，但有时可能会导致指向变量无法访问的情况。

#1