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Hello everyone!



I am trying to get an array of unique items which are objects of two keys



{id: "record ID", name: "name of record"}


To filter out duplicate items I use rather complicated way. I define 3 arrays:





  • one for keeping collected data possibly having duplicates and later for cleaned data


  • two others for keeping filtered ids and names





Code looks like this:



let d = [];


let u = [];


let v = [];





d = [{id:1, name:"a"},{id:3, name:"b"},{id:3, name:"b"}];





console.log(d);





u = [...new Set(d.map(d => d.id))];


v = [...new Set(d.map(d => d.name))];


d = [];


let m = 0;


while (m < u.length){ d[m] = {id:u[m],name:v[m]}; m++ }





console.log(d);


As you can see I am using a Set to filter out duplicates. Unfortunately, this works only for simpler arrays (or I do not know how to use it in my case). Is there any easier or brief way to do that? Any valuable suggestion is much appreciated.

Hi @Andrey_Kovalev - I would also reach for Set when trying to get a unique set of values, but Set only works with primitive values or object references (but not actual objects). Here’s a method that doesn’t use Set



let array = y


    {id:1, name:"a"},


    {id:3, name:"b"},


    {id:3, name:"b"},


    {id:1, name:"a"},


    {id:1, name:"a"},


];





const result = t];


const map = new Map();


for (let item of array) {


    if(!map.has(item.id)){


        map.set(item.id, true);


        result.push(item);


    }


}


console.log(result)


This uses Map to note whether or not the loop has already seen a specific id. If not, then the current object is added to the result array; if it has been seen, then we move onto the next item in the array.

@JonathanBowen thank you for your solution. I will definetely try it.

@JonathanBowen thank you for your solution. I will definetely try it.


@JonathanBowen your solution is twice faster than mine. Thanks again for demonstrating how to use Maps. This was new to me.

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