前端获取时间范围内的所有周数组集合，第一项为首月的首个周一

news2024/11/27 9:39:03

具体可实现的效果例如：

数据格式：

具体代码实现：

     /**
       * 获取当前日期的第一个周一是哪天
       * @params date - 'YYYY-MM'
       */
      function getMonthFirstWeekDay(date) {
        let year = new Date(date).getFullYear();
        let month = new Date(date).getMonth();
        for (let week = 1; week < 8; week++) {
          if (new Date(`${year}-${month + 1}-${week}`).getDay() === 1) {
            return week;
          }
        }
      }

      /**
       * 获取start日期到end日期的周集合
       * @params start - 'YYYY-MM'
       * @params end - 'YYYY-MM'
       */
      function getAllWeeks(start, end) {
        if (!start) return [];

        // 结束日期
        try {
          let endDate = end ? new Date(end) : new Date();
          let endYear = endDate.getFullYear();
          let endMonth = endDate.getMonth() + 2;
          if (endMonth > 11) {
            endMonth = "1";
            endYear++;
          }
          end = `${endYear}-${endMonth}`;

          const weeks = []; // 周数组
          let firstWeek = getMonthFirstWeekDay(start); // 周几
          let firstDate = `${start}-${firstWeek}`; // 第一周日期
          let endTimestamp = new Date(end).getTime(); // 不超过最后月份时间戳
          let prevTimestamp = new Date(firstDate).getTime(); // 第一周时间戳
          let oneDay = 24 * 60 * 60 * 1000; // 一天的时间戳偏移量

          while (prevTimestamp < endTimestamp) {
            let prevDate = new Date(prevTimestamp);
            let nextDate = new Date(prevTimestamp + oneDay * 6);

            let prevY = prevDate.getFullYear();
            let prevM = prevDate.getMonth() + 1;
            let prevD = prevDate.getDate();

            let nextY = nextDate.getFullYear();
            let nextM = nextDate.getMonth() + 1;
            let nextD = nextDate.getDate();

            weeks.push([
              {
                year: prevY,
                month: prevM,
                day: prevD,
                ymd: `${prevY}-${prevM}-${prevD}`,
                ym: `${prevY}-${prevM}`,
                md: `${prevM}-${prevD}`,
              },
              {
                year: nextY,
                month: nextM,
                day: nextD,
                ymd: `${nextY}-${nextM}-${nextD}`,
                ym: `${nextY}-${nextM}`,
                md: `${nextM}-${nextD}`,
              },
            ]);

            prevTimestamp += oneDay * 7;
          }

          return weeks;
        } catch (error) {
          return [];
        }
      }

      // 使用示例

      // 全部周
      const weeks = getAllWeeks("2023-12", "2024-01");
      console.log("weeks:", weeks);

      // 按月分组
      const weeksByMonth = Object.groupBy(weeks, (op) => op[0].ym);
      console.log("weeksByMonth:", weeksByMonth);

      // 按年分组
      const weeksByYear = Object.groupBy(weeks, (op) => op[0].year);
      console.log("weeksByYear:", weeksByYear);

需求简要描述一下吧