How to declare global variable inside function?

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

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

This is exactly what I want to do:

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

You have two problems:

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

2. Your function syntax is wrong. You need to have parentheses after the function name. Either of these are valid syntaxes for main:

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

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

int main() {
  int local_variable = 0;
}

or assign to a global variable like so:

int global_variable;

int main() {
  global_variable = 0;
}