removing duplicates in an array of objects

1let person = [{name: "john"}, {name: "jane"}, {name: "imelda"}, {name: "john"}];
2
3function removeDuplicates(data, key) {
4  
5  return [
6    ...new Map(data.map(item => [key(item), item])).values()
7  ]
8
9};
10
11console.log(removeDuplicates(person, item => item.name));

1let person = [
2{name: "john"}, 
3{name: "jane"}, 
4{name: "imelda"}, 
5{name: "john"},
6{name: "jane"}
7];
8
9const data = Array.from(new Set(person.map(JSON.stringify))).map(JSON.parse);
10console.log(data);

1arr.reduce((acc, current) => {
2  const x = acc.find(item => item.id === current.id);
3  if (!x) {
4    return acc.concat([current]);
5  } else {
6    return acc;
7  }
8}, []);

1// BEST ANSWER - LINEAR TIME SOLUTION
2
3const seen = new Set();
4const arr = [
5  { id: 1, name: "test1" },
6  { id: 2, name: "test2" },
7  { id: 2, name: "test3" },
8  { id: 3, name: "test4" },
9  { id: 4, name: "test5" },
10  { id: 5, name: "test6" },
11  { id: 5, name: "test7" },
12  { id: 6, name: "test8" }
13];
14
15const filteredArr = arr.filter(el => {
16  const duplicate = seen.has(el.id);
17  seen.add(el.id);
18  return !duplicate;
19});