错误：在“=”标记之前应有“:”、“,”、“;”、“}”或“__attribute__” [重复]

Question

为什么会弹出此错误（对于 int index = -1）。下面是这段代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>

#define Offset 12

int num_frames;

struct node
    {
        struct node* next;
        long data;
    };

struct page
{
    int index = -1;
    int frame = -1;
    int dirty = 0; //0 is clean, 1 is dirty
    int valid = 0; //0 is not, 1 is valid
    int referenced = 0; //0 is not, 1 is referenced
};

任何见解将不胜感激！

Answer 1

问题出在

struct page
{
    int index = -1;
    int frame = -1;
    int dirty = 0; //0 is clean, 1 is dirty
    int valid = 0; //0 is not, 1 is valid
    int referenced = 0; //0 is not, 1 is referenced
};

您定义了一个新类型struct page 并尝试在同一个声明中对其进行初始化。类型没有默认值。正确的做法是定义不带初始值的新类型struct page，然后使用这些值启动一个新的struct page 变量。