Filter array of object from another array

Question

I have two arrays. I want to filter one array which contains objects from another array.

let array1= [{date:1, count:4}, {date:3, count:6}];
let array2= [1,2,3,4         


        

Answer 1

You can use map() and find() methods for this. You don't need filter() because for each element you will return count or 0 so you can just use map().

let array1= [{date:1, count:4}, {date:3, count:6}];
let array2= [1,2,3,4];

var array = array2.map(function(e) {
  var f = array1.find(a => a.date == e);
  return f ? f.count : 0
});

console.log(array)