How to find third values comparing two values in javascript?

Question

Here I have two arrays array1 and array2 I want to find ids from array1 which array1's names matched with array2 values how to find ids in javascript ?

array1:

[ {id: 1, name: "Hindi"}
  {id: 2, name: "English"}
  {id: 3, name: "French"}
  {id: 4, name: "Russian"}
  {id: 5, name: "Urdu"}
  {id: 6, name: "Japanese"}
]

array2:

["Hindi", "Russian", "Urdu"]

I tried this code

console.log(array1.find(x => x.name === array2).id;

What would you expect from e.g. `"Hindi" === ["Hindi", "Russian", "Urdu"]`? Look into filtering and mapping arrays. — jonrsharpe, May 02 '19 at 07:12
@jonrsharpe no "Hindi" === "Hindi" , "Russian" === "Russian", "Urdu" === "Urdu" and want that ids in array like this [1, 4, 5] — Dharmesh, May 02 '19 at 07:14
That is **not** what you've written. Try decomposing this into smaller steps, e.g. how to check whether a given value is *in* (not *equal to*) an array. — jonrsharpe, May 02 '19 at 07:17
Possible duplicate of [Simplest code for array intersection in javascript](https://stackoverflow.com/questions/1885557/simplest-code-for-array-intersection-in-javascript) — George, May 02 '19 at 07:23

Maheer Ali · Accepted Answer · 2019-05-02T07:25:51.717

1

You can use filter() to get objects whose names are in the array.Then use map() to convert array of values to array of ids.

In your code you are comparing the string with array x.name === array2. You should use includes()

let arr = [ {id: 1, name: "Hindi"}, {id: 2, name: "English"}, {id: 3, name: "French"}, {id: 4, name: "Russian"}, {id: 5, name: "Urdu"}, {id: 6, name: "Japanese"} ]
let lang = ["Hindi", "Russian", "Urdu"];

let res = arr.filter(x => lang.includes(x.name)).map(x => x.id);
console.log(res)

edited May 02 '19 at 07:25

answered May 02 '19 at 07:13

Maheer Ali

35,834
5
42
73

@DDD Consider accepting the answer if it works for you. I don't know why I got a downvote eventhough the code works according to need of OP. – Maheer Ali May 02 '19 at 07:24

score 1 · Answer 2 · answered May 02 '19 at 07:14

You should use filter method in combination with map and destructuring

let arr1 = [ {id: 1, name: "Hindi"}, {id: 2, name: "English"}, {id: 3, name: "French"}, {id: 4, name: "Russian"}, {id: 5, name: "Urdu"}, {id: 6, name: "Japanese"} ], arr2 = ["Hindi", "Russian", "Urdu"];

console.log(arr1.filter(({name}) => arr2.includes(name)).map(({id}) => id));

score 0 · Answer 3 · edited May 02 '19 at 07:18

Try this:

 var a = [{
      id: 1,
      name: "Hindi"
    }, {
      id: 2,
      name: "English"
    }, {
      id: 3,
      name: "French"
    }, {
      id: 4,
      name: "Russian"
    }, {
      id: 5,
      name: "Urdu"
    }, {
      id: 6,
      name: "Japanese"
    }]
    var b = ["Hindi", "Russian", "Urdu"];
    var c = a.filter(function(i){
    return b.indexOf(i.name)>-1;
    });
    console.log(c); // New Array with filtered values

score 0 · Answer 4 · answered May 02 '19 at 07:29

This will work too :)

var a1 = [{
  id: 1,
  name: "Hindi"
}, {
  id: 2,
  name: "English"
}, {
  id: 3,
  name: "French"
}, {
  id: 4,
  name: "Russian"
}, {
  id: 5,
  name: "Urdu"
}, {
  id: 6,
  name: "Japanese"
}]
var a2 = ["Hindi", "Russian", "Urdu"];
var filter = a1.filter(function(i) {
  return a2.indexOf(i.name) > -1;
}).map(function(obj) {
  return obj.id;
});;
console.log(filter);

How to find third values comparing two values in javascript?

4 Answers4