Question

我想用JavaScript来生成当前日期的前四个星期日例如，如果当前日期是 2018-3-1 ，我想获得2018-2-25,2018-2-18,2018-2-11,2018-2-4。

我有这个代码，但它只给了我当前日期的前一个星期日我怎样才能获得前四个星期日？

var dt = new Date();
var currentWeekDay = dt.getDay();
var lessDays = currentWeekDay == 0 ? 6 : currentWeekDay - 0;
var sunday = new Date(new Date(dt).setDate(dt.getDate() -
  lessDays));

console.log(sunday);

Answer 1

一个想法是使用loop。将返回的星期日送回循环。
下面，我将返回的日期存储在一个数组中。

＆＃13;

var date = new Date();
var loop_count = 4;
var days = [];
var prev_sunday;
var loop_index;

function getPreviousSunday(date) {
  return new Date(
    new Date(date).setDate(
      date.getDate() - (date.getDay() || 7)
    )
  );
}

for (loop_index = 1; loop_index <= loop_count; loop_index++) {
  prev_sunday = getPreviousSunday(prev_sunday || date);
  days.push(prev_sunday);
}

console.log(date);
console.log(days);

＆＃13;

Answer 2

这是一种方法，可让您调整哪一天以及过去几天的频率。

function findPreviousDay(oDate, day, occurence){
 var weekday = [];
 var prevDays = [];

 weekday.sunday = 0;
 weekday.monday = 1;
 weekday.tuesday = 2;
 weekday.wednesday = 3;
 weekday.thursday = 4;
 weekday.friday = 5;
 weekday.saturday = 6;

 for(i=0;i<occurence;i++){
  prevDay = new Date(oDate).setDate(oDate.getDate()-oDate.getDay()+weekday[day.toLowerCase()]-i*7);
  prevDays.push(new Date(prevDay));
 }

 return prevDays;
}

var d = new Date("3/1/2018");

listOfDays = findPreviousDay(d, "sunday",4);

listOfDays.forEach(function(day){
    document.write(day+"<br/>");
});

Try it out!

如何获得当前日期javascript的前4个星期日

2 个答案: