Declaration of a function in c programming

Question

如果函数（例如a（））原型在函数内声明（比如main（）），是否意味着它不能用于main（）函数以外的函数？

Answer 1

No that does not mean that. If the other functions declare it too, then the function can be used by those other functions too.

int main(void) {
  void f(void); 
  f();
}

void g(void) {
  void f(void);
  f();
}

In this example, main declared function f locally and called it. But g does that same thing too. Both declarations refer to the same function.

Answer 2

Yes that is correct. That is true for all declarations within a particular scope. They are only available within the defining scope.

Of course, you can declare the same function in another scope, but I don't think that's what you meant.

Answer 3

通常，您能够在函数内声明的内容（例如变量）仅用于该函数。