C语言经典例题-switch case语句转换日期格式

        下面编写程序，用这种格式来显示日期。用户以月/日/年的格式录入日期，然后计算机显示出“法定”格式的日期:
Enter date (mm/dd/yy): 7/19/14
Dated this 19th day of July,2014.

# include <stdio.h>

int main()
{
	int month, day, year;
	
	printf("Enter date (mm/dd/yy): ");
	scanf("%d/%d/%d", &month, &day, &year);

	printf("Dated this %d", day);

	switch(day){
	case 1: case 21: case 31:
		printf("st");
		break;
	case 2: case 22:
		printf("nd");
		break;
	case 3: case 13: case 23:
		printf("rd");
		break;
	default: printf("th");
		break;
	}

	printf(" day of ");

	switch(month){
	case 1: printf("January"); break;
	case 2: printf("February"); break;
	case 3: printf("March"); break;
	case 4: printf("April"); break;
	case 5: printf("May"); break;
	case 6: printf("June"); break;
	case 7: printf("July"); break;
	case 8: printf("August"); break;
	case 9: printf("September"); break;
	case 10: printf("October"); break;
	case 11: printf("November"); break;
	case 12: printf("Decembery"); break;
	}

	printf(", 20%.2d.\n", year);

	return 0;
}		

        注意，%.2d用于显示年份的最后两位数字。如果用%d代替的话，那么将错误地显示倒数第二位为零的年份（将会把2001显示成201)。