BasicIO.c，RUN

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

//整数小数的输入
void BasicIO()
{
	int nValue;
	long long llValue;
	float fValue;
	double dValue;

	//%d %lld %f %lf分别对应int，long long, float, double 类型的输入
	//1. 如果类型不匹配，将出现运行错误
	//2. 只能空格隔开，不能加上','等其它分割符
	int count = scanf("%d %lld %f %lf", &nValue, &llValue, &fValue, &dValue);
	//scanf_s("%d %lld %f %lf", &nValue, &llValue, &fValue, &dValue); //或者
}

//菜单的实现方法
void Menu()
{
	int count = 0;

	int select;
	count = scanf("%d", &select);
	//实现菜单
	switch (select)
	{
	case 0:

		break;
	case 1:

		break;

	default:
		break;
	}


	//char类型和char字符串类型的scanf_s必须指定输入字符的个数
	char c;
	count = scanf("%c", &c);
	c = getchar();
	scanf_s("%c", &c, 1); //1个字符
	//实现菜单
	switch (c)
	{
	case 'A':
	case 'a':

		break;
	case 'B':
		break;
	default:
		break;
	}


	//char类型和char字符串类型的scanf_s必须指定输入字符的个数
	char msg[128];
	count = scanf("%s", msg);
	scanf_s("%s", msg, 128);

	if (strcmp(msg, "Here") == 0)
	{

	}
	else if (strcmp(msg, "There") == 0)
	{

	}
}

void Advanced()
{
	//循环输入，直到满足条件退出
	//scanf返回值来判断（返回获取数据的个数，如果输入正常，返回值应等于等待输入的变量的个数）
	//https://en.cppreference.com/w/c/io/fscanf
	char c0;
	while (scanf("%c", &c0) == 1)//scanf返回1个变量的值
	{
		if (c0 == '#')break; //退出循环
	}

	char c1, c2;
	while (scanf("%c %c", &c1, &c2) == 2)//scanf返回2个变量的值
	{
		if (c2 == '#')break; //退出循环
	}

	//getchar返回单个字符
	while ((c0 = getchar()) != '#')
	{

	}

	//检测连续的输入"ei"，用多个变量记录连续的输入
	char prev = '\0', cur;
	while ((cur = getchar()) != '#')
	{
		if (prev == 'e' && cur == 'i')
		{
			//检测到"ei"
		}
		//...
		prev = cur;
	}
}

//带空格的字符串输入
void IO_String()
{
	char buffer[128];

	fgets(buffer, 128, stdin);
	//gets(buffer); //或者
	//gets_s(buffer, 128); //或者

	puts(buffer);
	fputs(buffer, stdout); //或者
}


int main()
{
	Menu();

	IO_String();

	return 0;
}