years = [ Date, Date, Date ]
// This gets date ascending order but not sure how can i remove duplicate
this.years.sort(function(a, b) {
let dateA:any = new Date(a);
let dateB:any = new Date(b);
return (dateA - dateB);
});
console.log( this.years );
How can remove duplicate date in this sort function, Or do I need to write separately? and Is this script standard?
It's not possible to remove items while sorting as the sort function just move indexes. I would suggest you to get the unique elements first so the resulting array to sort is smaller and you don't sort elements that will be deleted.
Please, take a look at this answer to get the unique values:
const dates = [Date, Date, Date];
const uniqueDates = dates.filter((date, i, self) =>
self.findIndex(d => d.getTime() === date.getTime()) === i
)
And after that:
const uniqueDatesSorted = uniqueDates.sort((a, b) => a -b)
Hope it helps!
Date values. It works for other types, but I couldn't get it to work with Date. If you can provide a working example it can be helpful.
Ok, sort can't remove duplicates, so in my solution I removed the duplicates first with map and filter and then applied the sort.
let myArray = [new Date(2019, 06, 28), new Date(2019, 07, 28), new Date(2019, 06, 28), new Date(2019, 07, 14), new Date(2019, 07, 01), new Date(2019, 07, 16), new Date(2019, 07, 14)]
let unique = myArray.map((date) => +date)
.filter((date, i, array) => array.indexOf(date) === i)
.map((time) => new Date(time));
unique.sort((a, b) => a - b);
console.log(unique)
sortcan change the length of an array. You should usefilter. You can check this question.map(date => date.getTime())or if you want to be that cool guy, you can usedate => +date