Remove object from array based on array of some property of that object

Question

I have an array of objects (objList) that each has "id" property.

I have an array of strings (idsToRemove), representing IDs of the objects to remove from objList.

I find some solution but I fear it's slow, especially with the large list of objects with lots of properties. Is there more efficient way to do this?

var idsToRemove = ["3", "1"];
var objList = [{
    id: "1",
    name: "aaa"
  },
  {
    id: "2",
    name: "bbb"
  },
  {
    id: "3",
    name: "ccc"
  }
];

for (var i = 0, len = idsToRemove.length; i < len; i++) {
  objList = objList.filter(o => o.id != idsToRemove[i]);
}

console.log(objList);

Answer 1

Turn the idsToRemove into a Set so that you can use Set.prototype.has (an O(1) operation), and .filter the objList just once, so that the overall complexity is O(n) (and you only iterate over the possibly-huge objList once):

var idsToRemove = ["3", "1"];
var objList = [{
    id: "1",
    name: "aaa"
  },
  {
    id: "2",
    name: "bbb"
  },
  {
    id: "3",
    name: "ccc"
  }
];

const set = new Set(idsToRemove);
const filtered = objList.filter(({ id }) => !set.has(id));
console.log(filtered);

Note that Array.prototype.includes and Array.prototype.indexOf operations are O(N), not O(1), so if you use them instead of a Set, they may take significantly longer.

Answer 2

You can use Array.includes which check if the given string exists in the given array and combine it with an Array.filter.

const idsToRemove = ['3', '1'];

const objList = [{
    id: '1',
    name: 'aaa',
  },
  {
    id: '2',
    name: 'bbb',
  },
  {
    id: '3',
    name: 'ccc',
  },
];

const filteredObjList = objList.filter(x => !idsToRemove.includes(x.id));

console.log(filteredObjList);