#include <stdio.h>

int main()
{
	int a = 1;
	int b = 2;
	int c = (a > b, a = b + 10, a, b = a + 1);//逗号表达式
	printf("%d\n", a);
	printf("%d\n", b);
	printf("%d\n", c);

	return 0;
}

int main()
{
	int arr[10] = { 1,2,3,4,5 };
	//              0 1 2 3 4 5 6 7 8 9
	//数组的起始是有下标的，下标是0开始的
	printf("%d\n", arr[2]);//[] 下标引用操作符,arr 和 2 是[] 的两个操作数
	//3 + 5
	//
	return 0;
}

#include <string.h>

int Add(int x, int y)
{
	return x + y;
}

void test()
{
	printf("hehe\n");
}
int main()
{
	int len = strlen("abc");//() 函数调用操作符
	//() 的操作数是：strlen "abc"
	printf("%d\n", len);

	int c = Add(3, 5);//() 函数调用操作符
	//Add 3 5
	//对于函数调用操作符来说，最少有1个操作数

	printf("%d\n", c);

	test();

	return 0;
}

可变参数列表 - 参数的个数是变化的

struct Book
{
	char name[30];//成员
	char author[20];
	float price;
};

void Print(struct Book * p)
{
	printf("%s %s %.1f\n", (*p).name, (*p).author, (*p).price);
	printf("%s %s %.1f\n", p->name, p->author, p->price);
	//->
	//结构指针->成员名
}

int main()
{
	struct Book b1 = { "C语言第一课", "鹏哥", 66.5f };//书
	struct Book b2 = { "数据结构第一课", "杭哥", 88.6f };//书
	Print(&b1);
	Print(&b2);


	//printf("%s %s %.1f\n", b1.name, b1.author, b1.price);
	//printf("%s %s %.1f\n", b2.name, b2.author, b2.price);

	//结构体变量.成员名
	return 0;
}

#include<stdio.h>

int main()
{
	char c1 = 5;
	//00000000000000000000000000000101
	//00000101 - c1 (截断)
	char c2 = 127;
	//00000000000000000000000001111111
	//01111111 - c2
	char c3 = c1 + c2;
	//00000000000000000000000000000101
	//00000000000000000000000001111111
	//00000000000000000000000010000100
	//10000100 - c3
	//%d - 10进制的形式打印有符号的整数
	//11111111111111111111111110000100 - 补码
	//11111111111111111111111110000011
	//10000000000000000000000001111100 --> -124
	printf("%d\n", c3);
	//
	return 0;
}

#include<stdio.h>

int main()
{
	char a = 0xb6;//10110110
	short b = 0xb600;
	int c = 0xb6000000;

	if (a == 0xb6)
		printf("a");
	if (b == 0xb600)
		printf("b");
	if (c == 0xb6000000)
		printf("c");
	return 0;
}

#include<stdio.h>

//%d - 10进制的形式打印有符号的整数
//%u - 10进制的形式打印无符号的整数

int main()
{
	char c = 1;
	printf("%u\n", sizeof(c));
	printf("%u\n", sizeof(+c));
	printf("%u\n", sizeof(-c));
	return 0;
}

#include<stdio.h>

//相邻操作符优先级高的先算，低的后算
//相邻操作符的优先级相同的情况下，结合性起作用

//int main()
//{
//	int a = 2 + 3 + 5;
//
//	return 0;
//}

int fun()
{
	static int count = 1;
	return ++count;
}
int main()
{
	int answer;
	answer = fun() - fun() * fun();
	printf("%d\n", answer);//输出多少？
	return 0;
}

#include <stdio.h>

int main()
{
	int i = 1;
	int ret = (++i) + (++i) + (++i);

	printf("%d\n", ret);
	printf("%d\n", i);
	return 0;
}