filter duplicate array object javascript 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 duplicate objects based on id from array angular 8

function getUnique(arr, comp) {

                    // store the comparison  values in array
   const unique =  arr.map(e => e[comp])

                  // store the indexes of the unique objects
                  .map((e, i, final) => final.indexOf(e) === i && i)

                  // eliminate the false indexes & return unique objects
                 .filter((e) => arr[e]).map(e => arr[e]);

   return unique;
}

console.log(getUnique(arr,'id'));

Example 3: 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 4: remove duplicates objects from array javascript

function remove_duplicate_objects(data,prop) {
    var seen = {};
    data = data.filter(function (entry) {
      if (seen.hasOwnProperty(entry[prop])) {
        return false;
      }

      seen[entry.prop] = entry;
      return true;
    });
    return data
  }

const new_array = remove_duplicate_objects([array with objects inside])