c 断错误 demo

2021年10月8日20:55:05 星期五
一个简单的段错误例子。

示例：

// demo.c
#include <stdio.h>

struct fruit {
    int weight;
    char name[32];
};

int main()
{
    struct fruit fru[2] = {
        { .weight = 10, .name = "pear" },
        { .weight = 8, .name = "apple" }
    };

    for(int i = 0; i < sizeof(fru)/sizeof(struct fruit); i++)
    {
        printf("%d. %s:%d\n", fru[i].name, fru[i].weight);
    }

    return 0;
}

提问：这个代码有没有 bug?
答案：当然有，而且会产生错误。
正确代码

#include <stdio.h>

struct fruit {
    int weight;
    char name[32];
};

int main()
{
    struct fruit fru[2] = {
        { .weight = 10, .name = "pear" },
        { .weight = 8, .name = "apple" }
    };

    for(int i = 0; i < sizeof(fru)/sizeof(struct fruit); i++)
    {
        printf("%d. %s:%d\n", i, fru[i].name, fru[i].weight);
    }

    return 0;
}

效果

$ gcc demo.c
$ ./a.out
0. pear:10
1. apple:8