6.c

#include 

int main(void)
{
	int i = 5687;
	printf("i = %d \n", i);
	printf("i = %10d \n", i);	//设置字宽为10; 如果数字不足10个前补空格; 右对齐;
	printf("i = %-10d ", i);	//左对齐;
	printf("i = %010d \n", i);	//补0;

	double f = 1.3456789;
	printf("f = %lf \n", f);
	printf("f = %2.5lf \n", f);	//小数点前保留2位有效,后面5位有效;
	printf("f = %*.*lf \n", 4, 3, f);
	printf("f = %.4lf \n", f);
	
	float ff = 12.45f;
	printf("ff = %lf \n", ff);	//隐式转换;
	i = 'c'; 	//'c' ==> 默认转换为int ==> 再做赋值操作;
	
	int sum ;
	sum = i + '6';	//'6' ==> 整形;

	sum = 12 + 12.45;	//12 ==> double 12.00 + 12.45 ==> 24.45
						//24.45 ==> int  
	printf("sum = %d \n", sum);
	
	sum = (int)24.45;	//(类型)强制类型转换;
	printf("sum = %d \n", sum);

	char * p = (char *)0x12345678;

	return 0;

}