Comparing a string array with object array

Question

I want to compare two arrays

array1=["123',"456"];
array2=[{id":"001",name:"prashant"},{id:"123",name:"jhh"},{id:"123444",name"baak"},{id:"456",name"sxs"}];

my objective is to extract the objects from array2 whose ids match the values in array1.

Can someone help me with the optimal solution?

Does this answer your question? [Simplest code for array intersection in javascript](https://stackoverflow.com/questions/1885557/simplest-code-for-array-intersection-in-javascript) — AZ_, Jan 28 '20 at 09:43
The intersection code is for two arrays with a similar structure. Please look at my two arrays. the structure is different — viswanath, Jan 28 '20 at 09:46
that's even one step lesser than having both arrays of objects. — AZ_, Jan 28 '20 at 09:47
Also possible duplicate:　[How to remove object from array except matching value?](//stackoverflow.com/q/58127808) — Nick Parsons, Jan 28 '20 at 09:48
I extracted id's into a different array and then compared it that works. However I feel this can be optimised as this is a very crude method and can be optimised. — viswanath, Jan 28 '20 at 09:49
yes it can be if you convert your first array into a `Set`. then the method `array.includes` of `O(n)` will be changed to `Set.has` `O(1)` — AZ_, Jan 28 '20 at 09:51

score 2 · Accepted Answer · answered Jan 28 '20 at 09:45

First of all your second array (array2) is syntactically invalid.

You can try with Array.prototype.filter() and Array.prototype.includes()

var array1=["123","456"]; 
var array2 = [{id:"001",name:"prashant"},{id:"123",name:"jhh"},{id:"123444",name:"baak"},{id:"456",name:"sxs"}];

var res = array2.filter(i => array1.includes(i.id));
console.log(res);

Comparing a string array with object array

1 Answers1