React 从给定月份获取日历周数

Question

may someone can help me. I need to calculate the week numbers in a given month. Example the month july should have week number 26, 27, 28, 29 and 30. How do I calculate this and put them all into an array? Till now I only get the current calendar week number.

  const currentWeekNumber = useMemo(() => {
    const currentDate = new Date();
    const startDate = new Date(currentDate.getFullYear(), 0, 1);
    const days = Math.floor((currentDate.getTime() - startDate.getTime()) / (24 * 60 * 60 * 1000));

    const weekNumber = Math.ceil(days / 7);
    return weekNumber;
  }, []);

Answer 1

you can get the first day and last day of the current month and do the same process.

const range = (x,y) => {
  let array = [];
  for(let i = x; i<y; i++){
    array.push(i);
  }
  return array;
} 
 
const currentDate = new Date();
const startDate = new Date(currentDate.getFullYear(), 0, 1);

const firstDayOfMonth = new Date(currentDate.getFullYear(), currentDate.getMonth(),1);
const lastDayOfMonth = new Date(currentDate.getFullYear(), currentDate.getMonth()+1);

const difFirstDayOfMonth = Math.floor((firstDayOfMonth.getTime() - startDate.getTime()) / (24 * 60 * 60 * 1000) );
const difLastDayOfMonth = Math.floor((lastDayOfMonth.getTime() - startDate.getTime()) / (24 * 60 * 60 * 1000) );

const firstWeek = Math.ceil(difFirstDayOfMonth / 7);
const lastWeek = Math.ceil(difLastDayOfMonth / 7);

const rangeOfWeeks = range(firstWeek, lastWeek);

After that, you create an array from the week number of the first day of the month until the week number of the last day of the current month (range function).