c - 为什么循环没有停止？

Question

#include <stdio.h>
#include <stdlib.h>

#define NEWGEAR 15.0
#define USEDGEAR 5.0

int main() {
    int type;
    int num_items;
    float total;

    printf("Welcome to the market\n");
    printf("What would you like to do\n");
    printf("\t1-Buy New Gear\n");
    printf("\t2-Buy used gear\n");
    printf("\t3-Quit\n");

    scanf("%d", &type);

    while (type != 3) {
        switch (type) {
        case 1:
            printf("How many new items would you like?\n");
            scanf("%d", &num_items);
            total = num_items * 15.0;
            break;

这是代码不断询问您想要多少新商品的地方？

        case 2:
            printf("How many old items would you like?\n");
            scanf("%d", &num_items);
            total = num_items * USEDGEAR;
            break;

这是代码不断询问您想要多少旧元素的地方？ 案例 3: 休息；

        default:
            printf("Not a valid option\n");
            break;
        }
    }
    printf("Your total cost is %f\n",total);

    return 0;
}

我的两个选择都是循环

Answer 1

您永远不会将 type 变量更新为 3，因此 while 循环永远不会终止。尽管您确实有一个 break 语句，但它影响的是 switch 而不是它周围的 while 循环。