C語言及程式設計初步例程-25 用switch語句實現多分支結構
阿新 • • 發佈:2019-02-13
例:這是星期幾?
#include <stdio.h> int main() { int week; scanf("%d", &week); switch(week) { case 0: printf("Sunday\n"); case 1: printf("Monday\n"); case 2: printf("tuesday\n"); case 3: printf("wednesday\n"); case 4: printf("Thursday\n"); case 5: printf("Friday\n"); case 6: printf("Saturday\n"); default : printf("error\n"); } return 0; }
必要時,用break及時退出
#include <stdio.h> int main() { int week; scanf("%d", &week); switch(week) { case 0: printf("Sunday\n"); break; case 1: printf("Monday\n"); break; case 2: printf("tuesday\n"); break; case 3: printf("wednesday\n"); break; case 4: printf("Thursday\n"); break; case 5: printf("Friday\n"); break; case 6: printf("Saturday\n"); break; default : printf("error\n"); } return 0; }
多個case可以共用一組執行語句
#include <stdio.h> int main() { int week; scanf("%d", &week); switch(week) { case 1: case 2: case 3: case 4: case 5: printf("Workday\n"); break; case 0: case 6: printf("Weekend\n"); break; default : printf("error\n"); } return 0; }
簡單的四則“運算器”
#include <stdio.h>
int main()
{
float a,b;
char c;
printf("Please enter a,b and op:");
scanf("%f%c%f",&a,&c,&b);
switch(c)
{
case '+':
printf("%f+%f=%f\n",a,b,a+b);
break;
case '-':
printf("%f-%f=%f\n",a,b,a-b);
break;
case '*':
printf("%f*%f=%f\n",a,b,a*b);
break;
case '/':
if(b!=0.0) /*分母不能等於0*/
printf("%f/%f=%f\n",a,b,a/b);
else
printf("error!\n");
break;
default:
printf("error!\n");
break;
}
return 0;
}