使用reduce将一系列日期映射到时隙

Question

I have a class TimeSlotEntity and I have a range object with dates, that's, roughly speaking, is like this:

const slotRange = ['15:00', '15:30', '16:00', '16:30', '17:00', '17:30', '18:00'];

In code it looks like this:

const range = moments.range(startEventTime, endEventTime).by('minutes', { step: 30 });

The TimeSlotEntity class has date setters: setDateFrom(val: Moment) , setDateTo(val: Moment) ;

I would like to map the range to the corresponding TimeSlotEntity s so that the first slot would be from 15:00 to 15:30, the second one from 15:30 to 16:00, the third one from 16:00 to 16:30 etc.

How to do this with the javascript reduce function?

Answer 1

I know you asked specifically to use reduce , but I'd still just go with good old for loops.

const rangesArray = Array.from(ranges);

const timeSlotEntities = [];
for (let i = 0; i < rangesArray.length - 1; i++) {
  const timeSlotEntity = new TimeSlotEntity();

  timeSlotEntity.setDateFrom(rangesArray[i]);
  timeSlotEntity.setDateTo(rangesArray[i + 1]);

  timeSlotEntities.push(timeSlotEntity);
}

It would only work if the ranges array contains at least two elements.

If TimeSlotEntity can have an undefined end date, then you can modify the loop condition to i < ranges.length and that would work with ranges with only one element.