NodeJS/Javascript Finding Objects with same Property in different Array

Question

Im doing some stuff in NodeJS and need to compare Objects in different arrays for duplicate properties.

Example:

Items = [{"id": "10", "name": "milk"},{"id":"7", "name": "banana"},{"id":"47", "name": "cheese"},{"id":"6", "name":"carrot"}]
Fridge = [{"id":"19", "name": "cheese"},{"id": "10", "name": "milk"},{"id":"43","name": "egg"}, {"id":"6", "name":"not a carrot"}]

I want to get all the Objects in the array that have properties that are Included in both arrays. (Ugh bad explanation, see Example)

In this example, i want to get

Output = [{"id": "10", "name": "milk"},{"id":"6", "name":"not a carrot"}]

because only these 2 IDs exist in both Input Arrays.

How would i do this?

Mihai Alexandru-Ionut · Accepted Answer · 2018-05-24 12:03:30Z

2

You can use includes method in combination with filter.

Items = [{"id": "10", "name": "milk"},{"id":"7", "name": "banana"},{"id":"47", "name": "cheese"},{"id":"6", "name":"carrot"}]
Fridge = [{"id":"19", "name": "cheese"},{"id": "10", "name": "milk"},{"id":"43","name": "egg"}, {"id":"6", "name":"not a carrot"}]

result = Fridge.filter(item => Items.map(f => f.id).includes(item.id));
console.log(result);

answered May 24, 2018 at 12:03

Mihai Alexandru-Ionut

48.6k14 gold badges106 silver badges132 bronze badges

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

Comments

Raeesaa · Accepted Answer · 2018-05-24 12:08:36Z

You can easily achieve this using lodash.js as below:

In case you want to check for id only:

    let Items = [{"id": "10", "name": "milk"},{"id":"7", "name": "banana"},{"id":"47", "name": "cheese"},{"id":"6", "name":"carrot"}]
let Fridge = [{"id":"19", "name": "cheese"},{"id": "10", "name": "milk"},{"id":"43","name": "egg"}, {"id":"6", "name":"not a carrot"}]

let result = _.intersectionBy(Fridge, Items, 'id');

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>

Or if you want to compare entire object:

let Items = [{"id": "10", "name": "milk"},{"id":"7", "name": "banana"},{"id":"47", "name": "cheese"},{"id":"6", "name":"carrot"}]
let Fridge = [{"id":"19", "name": "cheese"},{"id": "10", "name": "milk"},{"id":"43","name": "egg"}, {"id":"6", "name":"not a carrot"}]

let result = _.intersectionWith(Items, Fridge, _.isEqual);

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>

`

Emeeus · Accepted Answer · 2018-05-24 13:35:53Z

Just another approach that could be useful to find duplicates with n arrays of objects as input:

var Items = [{"id": "10", "name": "milk"},{"id":"7", "name": "banana"},{"id":"47", "name": "cheese"},{"id":"6", "name":"carrot"}];
var Fridge = [{"id":"19", "name": "cheese"},{"id": "10", "name": "milk"},{"id":"43","name": "egg"}, {"id":"6", "name":"not a carrot"}];

var mergedArrray = Items.concat(Fridge); //merge all
//array1 = array1.concat(array2, array3, array4, ..., arrayN);    


var duplicateIds = [];
var uniqueIds = [];

//The idea is look for the id in uniqueIds, if exist push into duplicateIds
//if not push into uniqueIds 
mergedArrray.map((obj,v)=>{
(uniqueIds.indexOf(obj.id) == -1)?uniqueIds.push(obj.id):duplicateIds.push(obj.id);
})

console.log(duplicateIds);
console.log(uniqueIds);

This solution doesn't return an array of duplicates, just the reference.

Collectives™ on Stack Overflow

NodeJS/Javascript Finding Objects with same Property in different Array

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related