find date nearest to target in a list of dates

Question

I have a list of Date objects, and a target Date. I want to find the date in the list that's nearest to the target date, but only dates that are after the target date.

Example: 2008-10-1 2008-10-2 2008-10-4

With a target date of 2008-10-3, I want to get 2008-10-4

What is the best way to do it?

Answer 1

Sort the list of dates, read through it and then stop as soon as you get to a date that is >= the one you want.

list<Date> dates = new list<Date>();

//add all the dates;

dates.sort();

//now the list is ordered from oldest date to newest

Answer 2

Dominic's answer is the smartest way. Here is another way

List<Date> dateList = new List<Date>();

dateList.add(Date.Today()+1);
dateList.add(Date.Today()-2);
dateList.add(Date.Today()-1);

Date target = Date.today();
Integer days = 100000000;
Date nearest = target;
Integer count = 0;
do{
    Date d = dateList.get(count);
    if(d>target && days>target.daysBetween(d))
    {

            days = target.daysBetween(d);
            nearest = d;
    }
    count++;
}while(count < dateList.size());
System.debug('nearest'+nearest.day());