此程序旨在根据用户的输入显示视频游戏广告资源。用户需要确定循环使用num_of_games运行多长时间。我们必须使用开关循环来确定类型。它编译但无法正确显示。
#include <stdio.h>
#include <string.h>
#define MAX 16
typedef enum genre_type{ action = 0, rpg = 1, simulation = 2,
strategy = 3, sports = 4} genre_t;
typedef struct{
char title[MAX];
int num_sold;
genre_t genre;
}game_s;
// suppose to use functions and enum list for determining the genre
void get_game_info(game_s *ptr);
void display_inventory(game_s game[], int num_of_games);
int
main(void){
int i=0, num_of_games;
int c_game=0;
game_s game[num_of_games];
printf("How many games are there in inventory? ");
scanf("%d", &num_of_games);
fflush(stdin);
printf("\n");
while(c_game < num_of_games){
printf("\n");
get_game_info(&game[c_game]);
c_game++;
}
printf("\n");
display_inventory(game, num_of_games);
return(0);
}
void get_game_info(game_s *ptr)
{
int i, str_len, genre, num_sold;
printf("Title of game <maximum of 15 characters>: ");
gets(ptr->title);
str_len = strlen(ptr->title);
if(str_len >= 15){
printf("Title will be truncated\n");
ptr->title[MAX]= '\0';
}
printf("Number sold: ");
scanf("%d", &ptr->num_sold);
fflush(stdin);
printf("Genre (0-action, 1-rpg, 2-simulation, 3-strategy, 4-sports): ");
scanf("%d", &ptr->genre);
fflush(stdin);
if(ptr->genre>4){
printf("Not a valid genre");
fflush(stdin);
}
}
void display_inventory(game_s game[], int num_of_games)
{
int i, genre;
printf("Title\t\t\t\t\t\tQuantity Sold\t\t\t\t\t\tGenre");
printf("\n=====\t\t\t\t\t\t=============\t\t\t\t\t\t=====\n");
for(i=0; i < num_of_games; i++){
switch(genre){
case action: printf("Action"); break;
case rpg: printf("RPG"); break;
case simulation: printf("Simulation"); break;
case strategy: printf("Strategy"); break;
case sports: printf("Sports"); break;
default: puts("Not a choice. Try again"); break;
我认为这是造成大部分问题的原因。我不知道我是否正在使用游戏[I] .title和其他人调用结构。 我认为问题在于结构调用。如果我使用game_s [I] .title我得到＆＃34;预期表达式＆＃34;错误，如果我使用游戏[I] .title它没有正确打印
printf("%s\t\t\t\t\t\t%d\t\t\t\t\t\t%s", game[i].title, game[i].num_sold, game[i].genre);
printf("\n");
}
}
}
答案 0 :(得分：0)
我认为问题是write，因为send没有启动。
应该是：
recv答案 1 :(得分：0)
你的努力是值得称道的。您提供代码并善意地尝试理解为什么事情不起作用，但不幸的是，您的代码充满了错误。通过尝试使用未初始化的num_of_games声明VLA，您几乎可以立即调用 Undefined Behavior 。无论你从那一点开始在你的代码中做了什么，它只不过是一个骰子卷，无论你是否真的处理了某些东西或SegFaulted。
display_inventory中缺少输出（无论实际内存是什么）是由于printf语句放在switch语句的正文中。如果您break switch的{{1}}只是跳到default案例之下，则会完全跳出switch。因此，即使代码的其余部分是正确的，您也永远不会产生输出。
fflush(stdin)是错误的，并且除了windoze之外都会调用未定义的行为。它仅为世界其他地方的可搜索流定义 - 不使用它。相反，您可以定义一个简单的函数来清空stdin，并根据需要调用它。
编译时，始终使用 编译器警告启用 进行编译，不接受代码，直到干净地编译而不发出警告< / em>的。要启用警告，请将-Wall -Wextra添加到gcc编译字符串中。 （添加-pedantic以获得其他几个警告）。对于 VS （windoze上的cl.exe），请添加/Wall。对于clang，请添加-Weverything。阅读并理解每个警告。他们将识别任何问题，以及它们发生的确切线。您可以通过简单地聆听编译器告诉您的内容，从大多数教程中学到很多关于编码的知识。
您的代码中的错误数量过于庞大，无法逐项列出并与每个点说话，因此我在下面列出了注释以解决错误。
#include <stdio.h>
#include <stdlib.h> /* for EXIT_FAILURE */
#include <string.h>
#define MAX 16
typedef enum genre_type {
action = 0,
rpg = 1,
simulation = 2,
strategy = 3,
sports = 4
} genre_t;
typedef struct {
char title[MAX];
int num_sold;
genre_t genre;
} game_s;
// suppose to use functions and enum list for determining the genre
void get_game_info (game_s *ptr);
void display_inventory (game_s *game, int num_of_games);
void fflush_stdin();
int main (void) {
int num_of_games,
c_game = 0,
scnfrtn; /* scanf return - must always check EOF */
printf ("How many games are there in inventory? ");
for (;;) { /* loop until valid input or EOF (user cancels) */
if ((scnfrtn = scanf ("%d", &num_of_games)) == 1) {
fflush_stdin(); /* manually empty stdin */
break;
}
else if (scnfrtn == EOF) { /* user cancels? */
fprintf (stderr, "user canceled input.\n");
exit (EXIT_FAILURE);
}
/* handle error */
fprintf (stderr, "error: invalid input.\n");
fflush_stdin();
}
putchar ('\n'); /* don't printf a single-char */
/* declare VLA only AFTER num_of_games has a value */
game_s game[num_of_games];
memset (game, 0, sizeof game); /* optional, zero VLA */
while (c_game < num_of_games) {
putchar ('\n');
get_game_info (&game[c_game]);
c_game++;
}
putchar ('\n');
display_inventory (game, num_of_games);
return 0;
}
void get_game_info (game_s *ptr)
{
int scnfrtn; /* scanf return - must always check EOF */
size_t len = 0; /* strlen return is size_t */
printf ("Title of game <maximum of 15 characters>: ");
fgets (ptr->title, MAX, stdin); /* NEVER, NEVER, NEVER use gets */
len = strlen (ptr->title);
if (len && ptr->title[len-1] == '\n') /* check for trailing \n */
ptr->title[--len] = '\0'; /* overwrite with nul-character */
else /* warn of truncation */
fprintf (stderr, "error: title too long, truncated.\n");
for (;;) { /* loop until valid input or EOF (user cancels) */
printf ("Number sold: ");
if ((scnfrtn = scanf ("%d", &ptr->num_sold)) == 1) {
fflush_stdin();
break;
}
else if (scnfrtn == EOF) {
fprintf (stderr, "user canceled input.\n");
exit (EXIT_FAILURE);
}
fprintf (stderr, "error: invalid input.\n");
fflush_stdin();
}
for (;;) { /* loop until valid input or EOF (user cancels) */
printf ("Genre (0-action, 1-rpg, 2-simulation, "
"3-strategy, 4-sports): ");
if ((scnfrtn = scanf ("%d", (int*)&ptr->genre)) == 1) {
fflush_stdin();
break;
}
else if (scnfrtn == EOF) {
fprintf (stderr, "user canceled input.\n");
exit (EXIT_FAILURE);
}
else if (ptr->genre > 4) /* additional check for genre */
fprintf (stderr, "error: invalid genre.\n");
else
fprintf (stderr, "error: invalid input.\n");
fflush_stdin();
}
}
void display_inventory (game_s *game, int num_of_games)
{
int i;
printf ("%11s%-24s %-24s %s\n========================="
"==============================================\n",
" ", "Title","Quantity Sold", "Genre");
for (i = 0; i < num_of_games; i++) {
switch (game[i].genre) {
case action:
printf ("%-11s", "Action");
break;
case rpg:
printf ("%-11s", "RPG");
break;
case simulation:
printf ("%-11s", "Simulation");
break;
case strategy:
printf ("%-11s", "Strategy");
break;
case sports:
printf ("%-11s", "Sports");
break;
default:
puts ("Not a choice. Try again");
break;
}
printf ("%-24s %-24u %d\n", game[i].title,
game[i].num_sold, game[i].genre);
}
}
void fflush_stdin()
{
for (int c = getchar(); c != '\n' && c != EOF; c = getchar()) {}
}
（注意：使用printf 最小字段和修饰符来控制间距而不是一堆tabs一起使用）
示例使用/输出
$ ./bin/gamegenre
How many games are there in inventory? 3
Title of game <maximum of 15 characters>: first title
Number sold: 12
Genre (0-action, 1-rpg, 2-simulation, 3-strategy, 4-sports): 2
Title of game <maximum of 15 characters>: second title
Number sold: 13
Genre (0-action, 1-rpg, 2-simulation, 3-strategy, 4-sports): 1
Title of game <maximum of 15 characters>: third title
Number sold: 14
Genre (0-action, 1-rpg, 2-simulation, 3-strategy, 4-sports): 3
Title Quantity Sold Genre
=======================================================================
Simulation first title 12 2
RPG second title 13 1
Strategy third title 14 3
（注意：我不知道您的genre 描述的目标是什么，因此只需在每个开头输出上面的一行）
仔细看看，如果您有其他问题，请告诉我。