Unique Array by comparing elements of array React JS

Question

I have this array

array = [
         {id: "one", title: "new 1"},
         {id: "two", parent_id: "132132", title: "new 2"},
         {id: "three", parent_id: "132132", title: "new 3"},
         {id: "four", parent_id: "132132", title: "new 1"},
         {id: "one", parent_id: "132132", title: "new 1"}
        ]

We need

array = [
         {id: "two", parent_id: "132132", title: "new 2"},
         {id: "three", parent_id: "132132", title: "new 3"},
         {id: "four", parent_id: "132132", title: "new 1"},
         {id: "one", parent_id: "132132", title: "new 1"}
        ]

We need to compare elements to get unique array with different avoiding other elements

I have tried using this method

uniqueArray = (arr) => {
  return arr.filter((e, i, arr) => arr.findIndex(e2 => Object.keys(e2).every(prop => e2[prop] === e[prop])) === i);
};

As far as i can see all values are unique in this array, no duplicates. Be more specific based on what exactly do you want to filter this array. — jank
– jank, Commented Jul 10, 2019 at 7:05
You mean to say with unique id? What should be the behaviour for the duplicates? Which ones take precedence? The last one? — maazadeeb
– maazadeeb, Commented Jul 10, 2019 at 7:11
@ArpitVaishnav in the example array, the only one that is excluded does not have a parent_id. Is it safe to say that's the case for all duplicates? — Cat_Enthusiast
– Cat_Enthusiast, Commented Jul 10, 2019 at 8:56

Shubham Khatri · Accepted Answer · 2019-07-10 07:07:09Z

1

I prefer Array.reduce for this kind of things:

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

edited Jul 10, 2019 at 7:07

Shubham Khatri

284k58 gold badges431 silver badges411 bronze badges

answered Jul 10, 2019 at 7:06

Sultan H.

2,9383 gold badges14 silver badges23 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

octobus · Accepted Answer · 2019-07-10 08:59:14Z

0

If I understand you correctly, you want to return object without the property of parentId. If so you can use this.

array.filter(arr => arr.hasOwnProperty("parentId"))

answered Jul 10, 2019 at 8:59

octobus

1,2761 gold badge16 silver badges20 bronze badges

2 Comments

Arpit Vaishnav Over a year ago

thanks , how can we compare with id and keep parent id hash?

octobus Over a year ago

What you will get after this filter an array of objects with parentId properties. Do you want to also store the objects without the parentId somewhere else?

Collectives™ on Stack Overflow

Unique Array by comparing elements of array React JS

2 Answers 2

Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related