Question

在“th”中显示“Wednesday June 5th, 2008”等文字时，我需要一个函数来返回后缀数天。

只需要工作数字1到31（无需错误检查）和英语。

Answer 1

这是一个替代方案，它也适用于更大的数字：

static const char *daySuffixLookup[] = { "th","st","nd","rd","th",
                           "th","th","th","th","th" };

const char *daySuffix(int n)
{
    if(n % 100 >= 11 && n % 100 <= 13)
        return "th";

    return daySuffixLookup[n % 10];
}

Answer 2

以下功能适用于C：

char *makeDaySuffix (unsigned int day) {
    //if ((day < 1) || (day > 31)) return "";
    switch (day) {
        case 1: case 21: case 31: return "st";
        case 2: case 22:          return "nd";
        case 3: case 23:          return "rd";
    }
    return "th";
}

根据要求，它仅适用于1到31的数字。如果您想要（可能，但不一定）原始速度，您可以尝试：

char *makeDaySuffix (unsigned int day) {
    static const char * const suffix[] = {
        "st","nd","rd","th","th","th","th","th","th","th",
        "th","th","th","th","th","th","th","th","th","th"
        "st","nd","rd","th","th","th","th","th","th","th"
        "st"
    };
    //if ((day < 1) || (day > 31)) return "";
    return suffix[day-1];
}

你会注意到我已经注定要在那里办理登记手续了。如果甚至 slightest 可能会传递意外值，您可能想要取消注释这些行。

请记住，对于今天的编译器，对高级语言中更快的内容的天真假设可能不正确：测量，不要猜测。

Answer 3

const char *getDaySuffix(int day) {
    if (day%100 > 10 && day%100 < 14)
        return "th";
    switch (day%10) {
        case 1:  return "st";
        case 2:  return "nd";
        case 3:  return "rd";
        default: return "th";
    };
}

这个适用于任何数字，而不仅仅是1-31。

Answer 4

在这里查看我的问题：How to convert Cardinal numbers into Ordinal ones（这不是C＃）。

总结：看起来还没有办法，只要您使用有限的要求，就可以使用像发布的那样简单的功能。

如何为每月的几天提供后缀？

4 个答案: