C语言概述

一个简单的C程序示例

#include <stdio.h>   // #include 预处理器指令
int main(void){    // main()总是第一个被调用的函数
    int num;
    num = 1;
    printf("I am a simple");
    printf("computer\n");
    printf("my favorite number is %d because it is first\n",num);
    return 0;
}
// I am a simplecomputer
// my favorite number is 1 because it is first

#include <stdio.h>的作用相当于把stdio.h文件中的所有内容都输入到该行所在的位置

关键字

auto	extern	short	while
break	float	signed	_Alignas
case	for	sizeof	_Alignof
char	goto	static	_Bool
const	if	struct	_Complex
continue	inline	switch	_Generic
default	int	typedef	_Imaginary
do	long	union	_Noreturn
double	register	unsigned	_Static_assert
else	restrict	void	_Thread_lcoal
enum	return	volatile	_Atomic