c - c中函数和变量的静态作用域使用

Question

C 编程语言一书描述了静态变量的用法，主题what-does-static-mean-in-a-c-program

1. A static variable inside a function keeps its value between invocations.
2. A static global variable or a function is "seen" only in the file it's declared in

和书上解释的一样，但是第1点可以，第2点不可以。

我的代码:

标题.h

static int VAL = 15;
int canShare = 1;

static void hello(char c) {
printf("header file -> VAL: %d\n", VAL);
printf("header file -> canShare: %d\n", canShare);

printf("hello func -> %d\n", c);
}

主程序

#include <stdio.h>
#include "header.h"

main() {

printf("main -> VAL: %d\n", VAL+1);
printf("main -> canShare: %d\n", canShare+1);

hello('A');
}

输出

main -> VAL: 16
main -> canShare: 2
header file -> VAL: 15
header file -> canShare: 1
hello func -> 65

Answer 1

解释中存在细微的错误:

A static global variable or a function is "seen" only in the file it's declared in.

它仅在声明的翻译单元中可用。#include 指令字面上将头文件包含到翻译单元中，因此 TU 包含包含的头文件(如你可能会期望，语法上)。