输出示例

please enter your first name:
wang
please enter your last name:
fei
wang fei , your name contains 7 letters.

【结构作为参数传递并返回结构】

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

#define NLEN 30
struct namect {
    char fname[NLEN];
    char lname[NLEN];
    int letters;
};

struct namect getinfo(void);
struct namect makeinfo(struct namect);
void showinfo(struct namect);
char *s_gets(char *st, int n);

int main()
{
    struct namect person;

    person = getinfo();
    person = makeinfo(person);
    showinfo(person);

    return 0;
}

struct namect getinfo(void)
{
    struct namect temp;
    printf("please enter your first name:\n");
    s_gets(temp.fname,NLEN);
    printf("please enter your last name:\n");
    s_gets(temp.lname, NLEN);

    return temp;
}

//将结构person作为参数，创建一个新的结构info并将person的值拷贝到此结构
struct namect makeinfo(struct namect info)
{
    info.letters = strlen(info.fname) + strlen(info.lname);

    //统计完字母个数后，结果保存在info中，通过return 将info的值拷贝到person中，即返回一个结构
    return info;
}

void showinfo(struct namect info)
{
    printf("%s %s , your name contains %d letters.\n", info.fname, info.lname, info.letters);
}

char *s_gets(char *st, int n)
{
    char * ret_val;
    char * find;

    ret_val = fgets(st, n, stdin);
    if (ret_val)
    {
        find = strchr(st, '\n');
        if (find)
            *find = '\0';
        else
            while (getchar() != '\n')
                continue;
    }
    return ret_val;
}

【传递结构的地址】

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

#define NLEN 30
struct namect {
    char fname[NLEN];
    char lname[NLEN];
    int letters;
};

void getinfo(struct namect *);
void makeinfo(struct namect *);
void showinfo(const struct namect *);
char *s_gets(char * st, int n);

int main()
{
    struct namect person;

    getinfo(&person);
    makeinfo(&person);
    showinfo(&person);

    getchar();
    
    return 0;
}


void getinfo(struct namect * pst)
{
    printf("please enter your first name .\n");
    s_gets(pst->fname,NLEN);
    printf("please enter your last name.\n");
    s_gets(pst->lname, NLEN);
}

void makeinfo(struct namect *pst)
{
    pst->letters = strlen(pst->fname) + strlen(pst->lname);
}

void showinfo(const struct namect *pst)
{
    printf("%s %s,your name contains %d letters .\n",pst->fname,pst->lname,pst->letters);
}

char *s_gets(char *st, int n)
{
    char * ret_val;
    char * find;

    ret_val = fgets(st, n, stdin);
    if (ret_val)
    {
        find = strchr(st, '\n');
        if (find)
            *find = '\0';
        else
            while (getchar() != '\n')
                continue;
    }
    return ret_val;
}