Answers for "filter duplicate object in array javascript"

remove duplicate objects from array javascript

const addresses = [...]; // Some array I got from async call

const uniqueAddresses = Array.from(new Set(addresses.map(a => a.id)))
 .map(id => {
   return addresses.find(a => a.id === id)
 })

how to remove duplicate array object in javascript

let person = [
{name: "john"}, 
{name: "jane"}, 
{name: "imelda"}, 
{name: "john"},
{name: "jane"}
];

const obj = [...new Map(person.map(item => [JSON.stringify(item), item])).values()];
console.log(obj);

how to remove duplicate array object in javascript

let days = ["senin","senin","selasa","selasa","rabu","kamis", "rabu"];
let fullname = [{name: "john"}, {name: "jane"}, {name: "imelda"}, {name: "john"},{name: "jane"}];

// REMOVE DUPLICATE FOR ARRAY LITERAL
const arrOne = new Set(days);
console.log(arrOne);

const arrTwo = days.filter((item, index) => days.indexOf(item) == index);
console.log(arrTwo);


// REMOVE DUPLICATE FOR ARRAY OBJECT
const arrObjOne = [...new Map(person.map(item => [JSON.stringify(item), item])).values()];
console.log(arrObjOne);

const arrObjTwo = Array.from(new Set(person.map(JSON.stringify))).map(JSON.parse);
console.log(arrObjTwo);

Removing duplicates in an Array of Objects

// BEST ANSWER - LINEAR TIME SOLUTION

const seen = new Set();
const arr = [
  { id: 1, name: "test1" },
  { id: 2, name: "test2" },
  { id: 2, name: "test3" },
  { id: 3, name: "test4" },
  { id: 4, name: "test5" },
  { id: 5, name: "test6" },
  { id: 5, name: "test7" },
  { id: 6, name: "test8" }
];

const filteredArr = arr.filter(el => {
  const duplicate = seen.has(el.id);
  seen.add(el.id);
  return !duplicate;
});

delete duplicates in array of objects javascript

const arr = [
  { id: 1, name: "test1" },
  { id: 2, name: "test2" },
  { id: 2, name: "test3" },
  { id: 3, name: "test4" },
  { id: 4, name: "test5" },
  { id: 5, name: "test6" },
  { id: 5, name: "test7" },
  { id: 6, name: "test8" }
];

const filteredArr = arr.reduce((acc, current) => {
  const x = acc.find(item => item.id === current.id);
  if (!x) {
    return acc.concat([current]);
  } else {
    return acc;
  }
}, []);