Removing all certain duplicates from an array

Question

I have two different arrays and I want to remove all copies of first array's elements which exist in second one. I've tried some splice and indexOf methods but couldn't achieved it. Checked some of other posts but couldn't find what I'm exactly looking for. Here is an example code below. Thank you all.

let container = [1, 2, 2, 2, 3, 3, 3, 4, 5];
let removing = [2, 3];


function func(container, removing){
  let result = //i want to write a function there which will remove all duplicates of "removing" from "container".
  return result; // result = [1, 4, 5]
}

https://stackoverflow.com/questions/9229645/remove-duplicate-values-from-js-array — Zombie, Jun 21 '19 at 09:24

georg · Accepted Answer · 2019-06-21T09:52:36.420

9

Here you go

let container = [1, 2, 2, 2, 3, 3, 3, 4, 5];
let removing = [2, 3];


let difference = (a, b) => a.filter(x => !b.includes(x));

console.log(difference(container, removing))

If, for some reason, you're concerned about efficiency of this, you can replace the linear includes checks with O(1) Set lookups:

let difference = (a, b) => (s => a.filter(x => !s.has(x)))(new Set(b))

edited Jun 21 '19 at 09:52

answered Jun 21 '19 at 09:27

georg

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score 1 · Answer 2 · answered Jun 21 '19 at 09:28

Use filter with includes:

let container = [1, 2, 2, 2, 3, 3, 3, 4, 5];
let removing = [2, 3];


function func(container, removing){
  let result = container.filter(e => !removing.includes(e));
  return result;
}

console.log(func(container, removing));

ES5 syntax:

var container = [1, 2, 2, 2, 3, 3, 3, 4, 5];
var removing = [2, 3];


function func(container, removing){
  var result = container.filter(function(e) {
    return removing.indexOf(e) == -1;
  });
  return result;
}

console.log(func(container, removing));

score 1 · Answer 3 · answered Jun 21 '19 at 09:30

1

You can do it like this,

function func(container, removing){
  let result = container.filter(data => {
                   if(removing.indexOf(data) < 0) return true;})
  return result; // result = [1, 4, 5]
}

answered Jun 21 '19 at 09:30

Pavan Skipo

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score 0 · Answer 4 · answered Jun 21 '19 at 09:28

0

This will do:

function func(container, removing){
    let result = container.filter(x => !removing.includes(x));
    return result;
}

answered Jun 21 '19 at 09:28

Mu-Tsun Tsai

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score 0 · Answer 5 · answered Jun 21 '19 at 09:29

0

Try this:

let container = [1, 2, 2, 2, 3, 3, 3, 4, 5];
let removing = [2, 3];


const func = (container, removing) => container.filter(res=>!removing.includes(res));
  
console.log(func(container,removing));

answered Jun 21 '19 at 09:29

Ghoul Ahmed

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Removing all certain duplicates from an array

5 Answers5