Question

我想知道当月的星期天数。例如，2019年3月有5个星期日，所以我想达到这个数字。我已经尝试过在很多地方找到的这段代码，但是没有给出结果。

Calendar cal = Calendar.getInstance();
    int mes_cal = cal.get(Calendar.MONTH);
    int ano_cal = cal.get(Calendar.YEAR);

    int daysInMonth = cal.getActualMaximum(Calendar.DAY_OF_MONTH);

    int count = 0;
    for (int day = 1; day <= daysInMonth; day++) {
        cal.set(ano_cal, mes_cal, 1);
        int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);
        if (dayOfWeek == Calendar.SUNDAY) {
            count++;
            System.out.println(count);
        }
    }

解决方案（来自@primo建议的链接，仅作了一项更正）

Calendar cal = Calendar.getInstance();
    mes_cal = cal.get(Calendar.MONTH);
    ano_cal = cal.get(Calendar.YEAR);

public int countDayOccurence(int year, int month,int dayToFindCount) {
    Calendar calendar = Calendar.getInstance();
    calendar.set(year, month, 1);
    int daysInMonth = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);

    int count = 0;
    for (int day = 1; day <= daysInMonth; day++) {
        calendar.set(year, month, day);
        int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK);
        if (dayOfWeek == dayToFindCount) {
            count++;
        }
    }
    return count;
}

然后调用方法

int countSunday = countDayOccurence(ano_cal,mes_cal,Calendar.SUNDAY);

Answer 1

将日期作为校准设置中的第三个参数

Calendar cal = Calendar.getInstance();
int mes_cal = cal.get(Calendar.MONTH);
int ano_cal = cal.get(Calendar.YEAR);

int daysInMonth = cal.getActualMaximum(Calendar.DAY_OF_MONTH);

int count = 0;
for (int day = 1; day <= daysInMonth; day++) {
    cal.set(ano_cal, mes_cal, day);
    int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);
    if (dayOfWeek == Calendar.SUNDAY) 
        count++;
}

System.out.println("Total Sunday : "+count);

Answer 2

function getNumberOFSundayInCurrent() {

var now = new Date();
  var year = now.getFullYear();
  var month = now.getMonth();
  var cur_date = new Date(year,month,1);
  var count = 0;
  while (cur_date.getMonth() === month) {
    if(cur_date.toLocaleDateString('en-US',{weekday:'long'}) === 'Sunday')
      count += 1;
    cur_date.setDate(cur_date.getDate() + 1);
  }
  return count;
}

console.log(getNumberOFSundayInCurrent());

计算Android中当月的星期天数

2 个答案: