CODEWITHSUNDEEP
javascriptarrays
catmal
catmal

Reputation: 1758

Matching array of objects with array of values

If I have 2 arrays:

arr1: ["1","2"]
arr2: [{id: 1, color: "green"}, {id: 2, color: "yellow"}, {id: 3, color: "red"}]

And I want to obtain:

result: [{id: 1, color: "green"}, {id: 2, color: "yellow"}]

I am trying with

arr2.filter(
  e => arr1.indexOf(e.id) !== -1
);

But result is empty.

Upvotes: 0

Views: 62

Answers (3)

phi-rakib
phi-rakib

Reputation: 3302

You could use Array.prototype.filter() with Array.prototype.some() method to get the result.

const arr1 = ['1', '2'];
const arr2 = [
  { id: 1, color: 'green' },
  { id: 2, color: 'yellow' },
  { id: 3, color: 'red' },
];

const ret = arr2.filter((x) => arr1.some((y) => +y === x.id));
console.log(ret);

Another solution using Set Object.

const arr1 = ['1', '2'];
const arr2 = [
  { id: 1, color: 'green' },
  { id: 2, color: 'yellow' },
  { id: 3, color: 'red' },
];
const set = new Set(arr1);
const ret = arr2.filter((x) => set.has(x.id.toString()));
console.log(ret);

Upvotes: 2

Tigran Abrahamyan
Tigran Abrahamyan

Reputation: 776

Another solution is may be with .includes() method.

const arr1 =  ["1","2"]
const arr2 = [{id: 1, color: "green"}, {id: 2, color: "yellow"}, {id: 3, color: "red"}]

const result = arr2.filter(n => arr1.includes(String(n.id)));
console.log(result);

Upvotes: 0

Ramesh Reddy
Ramesh Reddy

Reputation: 10662

The problem with your code is that as your inputs have different types(id is a number but arr1 has strings), this arr1.indexOf(e.id) !== -1 will always be false.

Convert one of them to a number like this:

const arr1 = ["1","2"]
const arr2 = [{id: 1, color: "green"}, {id: 2, color: "yellow"}, {id: 3, color: "red"}]

const result = arr2.filter(el => arr1.some(aEl => el.id === +aEl))
console.log(result)

Alternatively, you can convert the ids to strings and use your existing code:

const arr1 = ["1", "2"],
  arr2 = [{
    id: 1,
    color: "green"
  }, {
    id: 2,
    color: "yellow"
  }, {
    id: 3,
    color: "red"
  }],

  result = arr2.filter(
    e => arr1.indexOf(e.id.toString()) !== -1
  );

console.log(result)

Upvotes: 2

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