How to get unique data from array of object by id in javascript

Question

Hello all I need help I am trying to get the unique data from an array of objects by id in JavaScript I am not able to fetch it below is my array

[
  {id: 408, customer_id: 2, bill_no: 381, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 409, customer_id: 3, bill_no: 382, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 410, customer_id: 4, bill_no: 383, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 411, customer_id: 6, bill_no: 384, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 412, customer_id: 7, bill_no: 385, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 413, customer_id: 8, bill_no: 386, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 414, customer_id: 9, bill_no: 387, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 387, customer_id: 2, bill_no: 360, bill_period: 'weekly', from_date: '2021-10-03'}
  {id: 388, customer_id: 3, bill_no: 361, bill_period: 'weekly', from_date: '2021-10-03'}
  {id: 389, customer_id: 4, bill_no: 362, bill_period: 'weekly', from_date: '2021-10-03'}
  {id: 390, customer_id: 6, bill_no: 363, bill_period: 'weekly', from_date: '2021-10-03'}
  {id: 391, customer_id: 7, bill_no: 364, bill_period: 'weekly', from_date: '2021-10-03'}
  {id: 392, customer_id: 8, bill_no: 365, bill_period: 'weekly', from_date: '2021-10-03'}
  {id: 393, customer_id: 9, bill_no: 366, bill_period: 'weekly', from_date: '2021-10-03'}
  {id: 380, customer_id: 2, bill_no: 353, bill_period: 'weekly', from_date: '2021-09-26'}
  {id: 381, customer_id: 3, bill_no: 354, bill_period: 'weekly', from_date: '2021-09-26'}
  {id: 382, customer_id: 4, bill_no: 355, bill_period: 'weekly', from_date: '2021-09-26'}
  {id: 383, customer_id: 6, bill_no: 356, bill_period: 'weekly', from_date: '2021-09-26'}
  {id: 384, customer_id: 7, bill_no: 357, bill_period: 'weekly', from_date: '2021-09-26'}
  {id: 385, customer_id: 8, bill_no: 358, bill_period: 'weekly', from_date: '2021-09-26'}
  {id: 386, customer_id: 9, bill_no: 359, bill_period: 'weekly', from_date: '2021-09-26'}
]

I want the unique data from the above array by customer_id with their latest id I want the result like the below code

[
  {id: 408, customer_id: 2, bill_no: 381, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 409, customer_id: 3, bill_no: 382, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 410, customer_id: 4, bill_no: 383, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 411, customer_id: 6, bill_no: 384, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 412, customer_id: 7, bill_no: 385, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 413, customer_id: 8, bill_no: 386, bill_period: 'weekly', from_date: '2021-10-10'}
  {id: 414, customer_id: 9, bill_no: 387, bill_period: 'weekly', from_date: '2021-10-10'}
]

Answer 1

There is no pretty ready made function, you need to roll your own; but it should be pretty simple to do. An excellent use case for a reducer!

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce

 const arr = [ {id: 408, customer_id: 2, bill_no: 381, bill_period: 'weekly', from_date: '2021-10-10'}, {id: 409, customer_id: 3, bill_no: 382, bill_period: 'weekly', from_date: '2021-10-10'}, {id: 410, customer_id: 4, bill_no: 383, bill_period: 'weekly', from_date: '2021-10-10'}, {id: 411, customer_id: 6, bill_no: 384, bill_period: 'weekly', from_date: '2021-10-10'}, {id: 412, customer_id: 7, bill_no: 385, bill_period: 'weekly', from_date: '2021-10-10'}, {id: 413, customer_id: 8, bill_no: 386, bill_period: 'weekly', from_date: '2021-10-10'}, {id: 414, customer_id: 9, bill_no: 387, bill_period: 'weekly', from_date: '2021-10-10'}, {id: 387, customer_id: 2, bill_no: 360, bill_period: 'weekly', from_date: '2021-10-03'}, {id: 388, customer_id: 3, bill_no: 361, bill_period: 'weekly', from_date: '2021-10-03'}, {id: 389, customer_id: 4, bill_no: 362, bill_period: 'weekly', from_date: '2021-10-03'}, {id: 390, customer_id: 6, bill_no: 363, bill_period: 'weekly', from_date: '2021-10-03'}, {id: 391, customer_id: 7, bill_no: 364, bill_period: 'weekly', from_date: '2021-10-03'}, {id: 392, customer_id: 8, bill_no: 365, bill_period: 'weekly', from_date: '2021-10-03'}, {id: 393, customer_id: 9, bill_no: 366, bill_period: 'weekly', from_date: '2021-10-03'}, {id: 380, customer_id: 2, bill_no: 353, bill_period: 'weekly', from_date: '2021-09-26'}, {id: 381, customer_id: 3, bill_no: 354, bill_period: 'weekly', from_date: '2021-09-26'}, {id: 382, customer_id: 4, bill_no: 355, bill_period: 'weekly', from_date: '2021-09-26'}, {id: 383, customer_id: 6, bill_no: 356, bill_period: 'weekly', from_date: '2021-09-26'}, {id: 384, customer_id: 7, bill_no: 357, bill_period: 'weekly', from_date: '2021-09-26'}, {id: 385, customer_id: 8, bill_no: 358, bill_period: 'weekly', from_date: '2021-09-26'}, {id: 386, customer_id: 9, bill_no: 359, bill_period: 'weekly', from_date: '2021-09-26'} ]; // reduce array to only relevant values to a single variable const filtered = arr.reduce((accumulator, current) => { // If customer data is already added to accumulator, don't add if (accumulator.find(x => x.customer_id === current.customer_id)) { return accumulator; } accumulator.push(current); return accumulator; }, []); console.log(filtered);