연습문제

안녕하세요.

int flag = scanf("%f", &library[count].price); 에서

int flag라고 변수를 따로만드는 이유는 무엇인가요?

scanf("%f", &library[count].price); 이렇게만 해두는거랑 무슨 차이가있나요?

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>
#define MAX_TITLE 40
#define MAX_AUTHOR 40
#define MAX_BOOKS 3

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

	ret_val = fgets(st, n, stdin); //공백을 포함한 문자열
	if (ret_val)
	{
		find = strchr(st, '\n'); //st에서 \n을 찾는다.
		if (find)
			*find = '\0';
		else
			while (getchar() != '\n')
				continue;
	}

	return ret_val;
}

struct book
{
	char title[MAX_TITLE];
	char author[MAX_AUTHOR];
	float price;
};

int main()
{
	struct book library[MAX_BOOKS] = { {"Empty","Empty",0.0f}, };
	//구조체배열 선언과 초기화
	int count = 0;

	while (1)
	{
		printf("Input a book title or press [Enter] to stop.\n>>");		
		if (s_gets(library[count].title, MAX_TITLE) == NULL) break;
		if (library[count].title[0] == '\0') break;
			
		printf("Input the author.\n>>");
		s_gets(library[count].author, MAX_AUTHOR);

		printf("Input the price.\n>>");
		int flag = scanf("%f", &library[count].price);
		while (getchar() != '\n')
			continue; //버퍼비우기

		count++;

		if (count == MAX_BOOKS)
		{
			printf("No more books.\n");
			break;
		}
	}

	if (count > 0)
	{
		printf("\nThe list of books:\n");
		for (int index = 0; index < count; index++)
			printf("\"%s\" written by %s: $%.1f\n",
				library[index].title, library[index].author, library[index].price);
	}
	else
		printf("No books to show.\n");

	return 0;
}