this is my test array:

let testArray = [{'Datum':'13/05/2024','ID':1},
{'Datum':'18/05/2013','ID':2},{'Datum':'01/05/2018','ID':3},
{'Datum':'31/05/2024','ID':4},{'Datum':'31/05/2024','ID':5}]

trying to order by Datum property ascending/descending order but it is not happening here is my logic:

_.orderBy(testArray, ['Datum'], ['asc']); //not working

using moment() js

 _.orderBy(testArray, (o) => {
            return moment(o.Datum).format('DD/MM/YYYY') //not happening either
          }, ['asc']);

i tried _.sortby and sort..but array its not arranging correctly, any hints? thanks

Your code wasn't working because you tried to format the date instead of actually telling Moment.js what format the date is. Instead of using moment(o.Datum).format("DD/MM/YYYY"), you should use moment(o.Datum, "DD/MM/YYYY"). That said below are the 2 solutions:

// Test array  
const testArray = [
  { Datum: "13/05/2024", ID: 1 },
  { Datum: "18/05/2013", ID: 2 },
  { Datum: "01/05/2018", ID: 3 },
  { Datum: "31/05/2024", ID: 4 },
  { Datum: "31/05/2024", ID: 5 },
];

Vanilla js with moment

This works by first mapping an array of items (item.Datum) into Moment.js date objects using the format DD/MM/YYYY. Then, it sorts these date objects in both ascending and descending order.

const mappedTestArray = testArray.map((item) =>
  moment(item.Datum, "DD/MM/YYYY")
);

// ASC ORDER
console.log(mappedTestArray.sort((a, b) => a.diff(b)));

// DESC ORDER
console.log(mappedTestArray.sort((a, b) => b.diff(a)));

The most important thing here is sorting part and how Array.sort() works . Here's the basic working :

• Less than 0: "a" is sorted to be a lower index than "b".
• Zero: "a" and "b" are considered equal, and no sorting is performed.
• Greater than 0: "b" is sorted to be a lower index than "a".

And using moment(...).diff(...) returns the difference i.e number so, a.diff(b) returns a negative number if a is before b, zero if a is the same as b, and a positive number if a is after b.

With lodash & moment ( yours corrected one )

This approach uses _.orderBy function for sorting. The sorting key is a parsed date, which is created by passing the Datum value through Moment.js with the format DD/MM/YYYY. By specifying ["desc"], the array is sorted in descending order.

const sortedArray = _.orderBy(
  testArray,
  (o) => {
    return moment(o.Datum, "DD/MM/YYY"); // the real bug fix ! 
  },
  ["desc"]
);

console.log(sortedArray);