使用Java基于迭代从字符串数组中查找日期答案

【问题标题】：Find day from String array based on iteration using Java使用Java基于迭代从字符串数组中查找日期
【发布时间】：2020-12-27 12:24:31
【问题描述】：

我有我的字符串数组和输入如下

S = "Tue" and K = 23

        String[] daysOfWeek = {"Mon","Tue","Wed","Thu","Fri","Sat","Sun"};

我的输入是“星期二”，并在 10 天后找到第二天。我期待答案为“星期五”

这是我的代码

        String[] daysOfWeek = {"Mon","Tue","Wed","Thu","Fri","Sat","Sun"};
    int day = Arrays.asList(daysOfWeek).indexOf(S);
    int n = K % 7;
    if((day + n) > 6) {
        int index = (day + n) % 6;
        //return daysOfWeek[ ];

    } else {
        return daysOfWeek[day + n ];

    }
    return null;

任何想法

【问题讨论】：

也许您应该发布您尝试过的代码。
@MarsAtomic，用代码更新
什么是K?...
你需要使用int index = (day + n) % 7;
您的代码有效吗？如果不是，它以何种方式行为不端？你得到什么结果而不是Fri？

标签： java dayofweek

【解决方案1】：

您可以使用java.time.DayOfWeek 而不是重新发明轮子。

例如：

DayOfWeek dayOfWeek = DayOfWeek.TUESDAY;
DayOfWeek dayOfWeek1 = dayOfWeek.plus(10);
System.out.println(dayOfWeek1); // FRIDAY

【讨论】：

【解决方案2】：

要简单！

private static final String[] DAYS_OF_WEEK = { "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" };
private static final Map<String, Integer> MAP = Map.of(DAYS_OF_WEEK[0], 0, DAYS_OF_WEEK[1], 1,
        DAYS_OF_WEEK[2], 2, DAYS_OF_WEEK[3], 3, DAYS_OF_WEEK[4], 4, DAYS_OF_WEEK[5], 5, DAYS_OF_WEEK[6], 6);

public static String find(String dayOfWeek, int days) {
    return DAYS_OF_WEEK[(MAP.get(dayOfWeek) + days) % 7];    // NPE if not found
}

【讨论】：

【解决方案3】：

你可以对之后的天数做模7，然后你可以根据输出找到将索引从起始位置移动到结果。

【讨论】：

【解决方案4】：

混合方法 -

String[] daysOfWeek = {"Mon","Tue","Wed","Thu","Fri","Sat","Sun"};
int today = LocalDate.now().getDayOfWeek().getValue()-1;
for (int i = 0; i < 31; i++) {
    System.out.println(daysOfWeek[today] + " >>>     " + i + "  - " + daysOfWeek[(today+i)%7]);
}

【讨论】：