Remove entry from array using another array

Question

Not sure how do to this, so any help is greatly appreciated

Say I have :

const array1 = [1, 1, 2, 3, 4];
const array2 = [1, 2];

Desired

Answer 1

IMO using array2 as object instead of array will be most performant way.

Here on first find of key we change the value in object so we do not filter that value again as desired in output.

const array1 = [1, 1, 2, 3, 4];
const array2 = Object.create(null,{
  1:{writable: true,value:false}, 
  2:{writable: true,value:false}
})


let op = array1.filter(e=> {
  if(array2[e] === false){
    array2[e] = true
    return false
  }
  return true
})

console.log(op)

On Side note:- With object.create we are creating a object without a prototype so it do not search for values in complete prototype chain.