将字符串转换为日期格式并检索周数字

// 字符串转换为日期格式
var dateString = "2022-01-01";
var dateObject = new Date(dateString);

// 获取周数字
var weekNumber = getWeekNumber(dateObject);
console.log(weekNumber);

// 获取周数字的函数
function getWeekNumber(date) {
  var target = new Date(date.valueOf());
  target.setDate(target.getDate() + 3 - (target.getDay() + 6) % 7);
  var firstThursday = target.valueOf();
  target.setMonth(0, 1);
  if (target.getDay() !== 4) {
    target.setMonth(0, 1 + ((4 - target.getDay()) + 7) % 7);
  }
  return 1 + Math.ceil((firstThursday - target) / 604800000);
}

import datetime

# 字符串转换为日期格式
date_string = "2022-01-01"
date_object = datetime.datetime.strptime(date_string, "%Y-%m-%d")

# 获取周数字
week_number = date_object.isocalendar()[1]
print(week_number)

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class Main {
  public static void main(String[] args) throws Exception {
    // 字符串转换为日期格式
    String dateString = "2022-01-01";
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
    Date dateObject = sdf.parse(dateString);

    // 获取周数字
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(dateObject);
    int weekNumber = calendar.get(Calendar.WEEK_OF_YEAR);
    System.out.println(weekNumber);
  }
}