remove duplicate entries from object array js code example

Example 1: how to remove duplicate array object in javascript

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

function removeDuplicates(data, key) {
  
  return [
    ...new Map(data.map(item => [key(item), item])).values()
  ]

};

console.log(removeDuplicates(person, item => item.name));

Example 2: remove duplicates objects from array javascript

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

Example 3: combine 2 "arrays with objects" and remove object duplicates javascript

// Join Without Dupes.
const joinWithoutDupes = (A, B) => {
  const a = new Set(A.map(x => x.item))
  const b = new Set(B.map(x => x.item))
  return [...A.filter(x => !b.has(x.item)), ...B.filter(x => !a.has(x.item))]
}

// Proof.
const output = joinWithoutDupes([{item:"apple",description: "lorem"},{item:"peach",description: "impsum"}], [{item:"apple", description: "dolor"},{item:"grape", description: "enum"}])
console.log(output)