C语言学习记录1

#include <stdio.h>
int main(void)
{
	int cen,mm;
	cen =2;
	mm =10*cen ;
	printf("%d cen is equal %d mm \n ",cen,mm);
	return 0;
}

#include <stdio.h>
int main (void) 
{ 
printf("how are you\n");
 return 0; 
}

#include <stdio.h> 
int main(void) 
{ 
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; 

}

/*  %d是占位符

#include <stdio.h>
void butler(void); 
int main(void)
{
	printf("I will summon the butler function.\n");
	butler();
	printf("Yes. Bring me some tea and writeable DVDs.\n");
	
	return 0;
} 
	void butler(void)
{
	printf("You rang ,sir?\n");
}

butler（）函数在程序中用到了三次，第一次是函数原型，第二次是函数调用，第三次是函数定义；

void butler（void）第一个void代表函数没有返回值，第二个void代表函数不带参数；

#include <stdio.h>
void butler(void); 
int main(void)
{
	
	butler();
	
	
	
	return 0;
} 
	void butler(void)
{
	printf("smile!smile!smile!\nsmile!smile!\nsmile!");

}

#include <stdio.h>
void compare(int a,int b);
int main (void)
{
    int a;
	int b;
	printf("请输入一个数:");
	scanf("%d",&a);
    printf("请输入一个数:");   
    scanf("%d",&b);
	compare(a,b);
	return 0;
	
}
 void compare(int a,int b)
{
	
if (a<b)
	printf("%d is the biger\n%d is the smaller",b,a);
	else
	printf("%d is the smaller\n%d is the biger",b,a);	
}