Remove duplicate objects in array, based on only one value in the objects

Question

I was working on some code that return the unique objects in an array.

I found some code that does the trick, but it's not exactly what I need.

Right now let's say I have this array:

restuls= [
        {
            name: "name 1",
            description: "",
            group: "group 1"
        },
        {
             name: "name 1",
            description: "",
            group: "group 1"
        },
        {
            name: "name 1",
            description: "",
            group: "group 2"
        },
]

With the code below, I find all unique objects in this array, meaning, if ANY of the values in the object are different, it will be a unique. So, in this case It will return 2 objects (because on the 3rd object --> group: "group 2").

   var array = results,
      unique = Array.from(
        new Set(array.map(o => JSON.stringify(o))),
        s => JSON.parse(s)
       );

What I actually want is that it removes all duplicate objects, but only looking at "name" So, in this case, all 3 objects have the same name, so only one should be displayed.

Any ideas?

Does this answer your question? [Create array of unique objects by property](https://stackoverflow.com/questions/18773778/create-array-of-unique-objects-by-property) — VLAZ, Aug 18 '20 at 05:38
Also relevant: [JavaScript: Remove duplicates of objects sharing same property value](https://stackoverflow.com/q/32238602) — VLAZ, Aug 18 '20 at 05:38

score 1 · Accepted Answer · answered Aug 18 '20 at 05:36

You can do this using for and a Set -

const input =
  [{name: "name 1",description: "",group: "group 1"},{name: "name 1",description: "",group: "group 1"},{name: "name 1",description: "",group: "group 2"},]

const result =
  []
  
const seen =
  new Set
  
  
for (const v of input)
  if (seen.has(v.name))
    continue
  else
    (result.push(v), seen.add(v.name))
    
console.log(result)

Output -

[
  {
    "name": "name 1",
    "description": "",
    "group": "group 1"
  }
]

Or using a Map -

const input =
  [{name: "name 1",description: "",group: "group 1"},{name: "name 1",description: "",group: "group 1"},{name: "name 1",description: "",group: "group 2"},]
 
const seen =
  new Map
    
for (const v of input)
  if (seen.has(v.name))
    continue
  else
    seen.set(v.name, v)

const result =
  Array.from(seen.values())
  
console.log(result)

Output -

[
  {
    "name": "name 1",
    "description": "",
    "group": "group 1"
  }
]

score 0 · Answer 2 · answered Aug 18 '20 at 05:36

results= [
        {
            name: "name 1",
            description: "",
            group: "group 1"
        },
        {
             name: "name 1",
            description: "",
            group: "group 1"
        },
        {
            name: "name 1",
            description: "",
            group: "group 2"
        },
]

const map = new Map();

results.forEach(x => {
  if(!map.has(x.name))
  { map.set(x.name, x) }
});

const arr = Array.from(map).map(x => x[1]);
console.log(arr)

Remove duplicate objects in array, based on only one value in the objects

2 Answers2