在C語言中使用枚舉類型在switch case語句中非常方便。首先需要定義一個枚舉類型，然后在switch case中使用這個枚舉類型的值來進行判斷。以下是一個簡單的示例：

#include <stdio.h>

enum Weekday {Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday};

int main() {
    enum Weekday today = Wednesday;

    switch (today) {
        case Monday:
            printf("Today is Monday\n");
            break;
        case Tuesday:
            printf("Today is Tuesday\n");
            break;
        case Wednesday:
            printf("Today is Wednesday\n");
            break;
        case Thursday:
            printf("Today is Thursday\n");
            break;
        case Friday:
            printf("Today is Friday\n");
            break;
        case Saturday:
            printf("Today is Saturday\n");
            break;
        case Sunday:
            printf("Today is Sunday\n");
            break;
        default:
            printf("Invalid day\n");
            break;
    }

    return 0;
}

在上面的示例中，我們首先定義了一個枚舉類型Weekday，包括了每個星期幾的枚舉值。然后在main函數中定義了一個變量today，并初始化為Wednesday。在switch case語句中，根據today的值來輸出對應的星期幾。

使用枚舉類型在switch case語句中可以使代碼更清晰易讀，枚舉值的名稱可以給代碼增加可讀性，并且可以避免使用魔術數值。