Determining the minimum and maximum date in an array object

Question

I have an array object that has a date field like this

    settledDate: "12-19-2018"
    settledDate: "12-12-2018"
    settledDate: "10-19-2018"
    settledDate: "10-12-2018"

I will like to determine the minimum and maximum date in this array.

I tried this but no luck

    const maxDate = new Date(Math.max.apply(null, this.props.form.details.bulkDetailsInvoices.settledDate)); 

    const minDate = new Date(Math.min.apply(null, this.props.form.details.bulkDetailsInvoices.settledDate));

Any ideas on what I can do to make this work?

Possible duplicate of [Min/Max of dates in an array?](https://stackoverflow.com/questions/7143399/min-max-of-dates-in-an-array) — Tom Faltesek, Sep 30 '19 at 20:14

Taki · Accepted Answer · 2019-09-30T21:02:39.863

2

Sort the array by date and pick the first and the last ones :

const dates = [
  { settledDate: "12-19-2018" },
  { settledDate: "12-12-2018" },
  { settledDate: "10-19-2018" },
  { settledDate: "10-12-2018" }
];

const sorted = dates.sort((a, b) => new Date(a.settledDate) - new Date(b.settledDate));

const minDate = sorted[0];
const maxDate = sorted.reverse()[0];

console.log('maxDate : ', maxDate.settledDate);
console.log('minDate : ', minDate.settledDate);

edited Sep 30 '19 at 21:02

answered Sep 30 '19 at 20:15

Taki

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I think you have this the other way round. From your console.log maxDate comes first and 10-12-2018 is not the maximum date right? – Baba Sep 30 '19 at 20:44
@user2320476 yes, i fixed the answer – Taki Sep 30 '19 at 21:02

score 1 · Answer 2 · answered Sep 30 '19 at 20:24

Here is a linear time O(n) solution. (I didn't find any linear time solution in linked duplicate question.)

const dates = [
  { settledDate: "12-19-2018" },
  { settledDate: "12-12-2018" },
  { settledDate: "10-19-2018" },
  { settledDate: "10-12-2018" }
];

let maxDate = dates[0];
let minDate = dates[0];

dates.forEach(item => {
 if (new Date(item.settledDate) < new Date(minDate.settledDate)) {
   minDate = item;
 }
 
 if (new Date(item.settledDate) > new Date(minDate.settledDate)) {
   maxDate = item;
 }
});

console.log("minDate:", minDate);
console.log("maxDate:", maxDate);

Determining the minimum and maximum date in an array object

2 Answers2