如何用js获取当年周数列表以及当前日期是第几周

function getWeekList() {
  const currentYear = new Date().getFullYear();
  const firstDayOfYear = new Date(`${currentYear}-01-01`);
  const firstThursday = new Date(firstDayOfYear);
  firstThursday.setDate(
    firstDayOfYear.getDate() + ((4 - firstDayOfYear.getDay() + 7) % 7) + 1
  );

  const weekList = [];
  let currentWeek = 1;

  while (firstThursday.getFullYear() === currentYear) {
    weekList.push({ value: currentWeek, text: `第${currentWeek}周` });
    firstThursday.setDate(firstThursday.getDate() + 7);
    currentWeek++;
  }

  return weekList;
}

const weekList = getWeekList();
console.log(weekList);

/* 打印结果
[
  { value: 1, text: '第1周' },
  { value: 2, text: '第2周' },
  { value: 3, text: '第3周' },
  // ... 其他周数
]
*/

// 获取当前日期是一年中的第几周的函数
function getWeekNumber(date) {
  // 设置 Date 对象的 firstDayOfWeek 为周一
  date.setHours(0, 0, 0, 0);
  // 设置 Date 对象的 firstDayOfYear 为 1 月 1 日
  date.setDate(date.getDate() + 4 - (date.getDay() || 7));
  // 计算当前日期是一年中的第几周
  const yearStart = new Date(date.getFullYear(), 0, 1);
  const weekNo = Math.ceil((((date - yearStart) / 86400000) + 1) / 7);
  return weekNo;
}

// 获取当前日期
const currentDate = new Date();

// 获取当前年份
const currentYear = currentDate.getFullYear();

// 获取当前日期是一年中的第几周
const weekNumber = getWeekNumber(currentDate);

// 输出结果
console.log(`${currentYear}年第${weekNumber}周`);