Javascript remove duplicated object from array

Question

i'm having trouble to remove duplicated object from my array

example:

var list = [{place:"AAA",name:"Me"}, {place:"BBB",name:"You"}, {place:"AAA",name:"Him"}];

in this example i have 3 objects, and i want to remove the object that have the duplicated place

FYI that's not an array - it's a syntax error. You need to replace the brackets with `[]` — Rory McCrossan, Jul 13 '15 at 16:13
First you have to decide, which one of them you want to keep. OR you want to remove both? — Shrinivas Shukla, Jul 13 '15 at 16:14
@MarcosViniciusdeSouzaGouve http://stackoverflow.com/questions/2218999/remove-duplicates-from-an-array-of-objects-in-javascript — Sudhansu Choudhary, Jul 13 '15 at 16:22
You can get an idea how to remove it from here: https://stackoverflow.com/questions/26832580/javascript-remove-duplicates-from-text-array/44117341#44117341 — Haythem HADHAB, May 22 '17 at 16:04

score 1 · Answer 1 · answered Jul 13 '15 at 16:50

1

Just in case someone wonders: underscore.js solution:

var list = [{place:"AAA",name:"Me"}, {place:"BBB",name:"You"}, {place:"AAA",name:"Him"}];

_.uniq(list, function(item, key, a) { 
    return item.place;
})

Example Fiddle

answered Jul 13 '15 at 16:50

SDekov

9,276
1
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Safeer Hussain · Answer 2 · 2015-07-13T17:05:54.537

1

A simple one:

var list = [{place:"AAA",name:"Me"}, {place:"BBB",name:"You"}, {place:"AAA",name:"Him"}];

list.forEach(function(i) {
  var duplicates = list.filter(function(j) {
    return j !== i && j.place == i.place;
  });
  duplicates.forEach(function(d) { list.splice(list.indexOf(d), 1); });
});

// list = [{place:"AAA",name:"Me"}, {place:"BBB",name:"You"}];
document.write(JSON.stringify(list));

edited Jul 13 '15 at 17:05

answered Jul 13 '15 at 16:57

Safeer Hussain

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score 0 · Answer 3 · answered Jul 13 '15 at 16:21

Try this.

var result = {};
for (i = 0, n = arr.length; i < n; i++) {
    var item = arr[i];
    result[ item.place + " - " + item.name ] = item;
}

Loop the result again, and recreate the array.

i = 0;    
for(var item in result) {
    clearnArr[i++] = result[item];
}

score 0 · Answer 4 · answered Jul 13 '15 at 16:22

Create a object to store the items by their place value, as the new item with the same key will overwrite the old one, this will easily remove all dulplicates.

var list = [{place:"AAA",name:"Me"}, {place:"BBB",name:"You"}, {place:"AAA",name:"Him"}];
var removeDuplicate = function(list) {
  var keyStore = {};
  var output = [];
  // If you want to creata totally new one from old, use 
  // list = JSON.parse(JSON.stringify(list));
  // The above commented out code will create a copy of list, so the items in output will not affect the original ones.
  list.forEach(function(item) {
    // new one overwrites old one.
    keyStore[item.place] = item;
  });
  
  var key;
  for (key in keyStore) {
    output.push(keyStore[key]);
  }
  
  return output;
};

console.log(removeDuplicate(list));

score 0 · Accepted Answer · answered Jul 13 '15 at 16:41

As you added:

i want to remove just one, dont matter wich one

If you want to remove duplicated items and keep only the first occcurence of particular place, you can simply use a simple loop to re-create a new array from the input:

var list = [{place:"AAA",name:"Me"}, {place:"BBB",name:"You"}, {place:"AAA",name:"Him"}];

var uniqPlace = function(array){
    var result = [];
    array.forEach(function(el){
        if (result.filter(function(n){ return n.place === el.place }).length==0){
            result.push(el);
        }
    })
    return result;
}

Output:

uniqPlace(list);

[{"place":"AAA","name":"Me"},{"place":"BBB","name":"You"}]

score 0 · Answer 6 · answered Dec 07 '19 at 07:50

3 way to remove duplicate objects from array

let list = [{place:"AAA",name:"Me"}, 
            {place:"BBB",name:"You"}, 
           {place:"AAA",name:"Him"}];



let output1 = Array.from(new Set(list.map(list=>list.place))).map(place=>{
  return {
   place: place,
   name: list.find(a=>a.place===place).name
  }
})
console.log('------------------------1st way')
console.log(output1)

let output2 = list.reduce((accumulator, element) => {
     if (!accumulator.find(el => el['place'] === element['place'])) {
          accumulator.push(element);
      }
     return accumulator;
   },[]);
console.log('------------------------2nd way')
console.log(output2)


const output3 = [];
const map = new Map();
for (const object of list) {
    if(!map.has(object.place)){
        map.set(object.place, true);
        output3.push({
            place: object.place,
            name: object.name
        });
    }
}
console.log('------------------------3rd way')
console.log(output3)

Javascript remove duplicated object from array

6 Answers6