Determine the difference between values ​​in an object and an array

Question

I have the following array of objects and numbers. How to tell which number in the array does not exist as an id in the object? In the example below, I want 1453.

[
  {id: 60, itemName: 'Main Location - 1100 Superior Road - Cleveland'}
  {id: 1456, itemName: 'Third Location - 107,West 20th Street,Manhattan - New York'}
]

[60, 1453, 1456]

Answer 1

For more data items and more id, I would choose one to create Set via mapping the id... of each itemList

item

const idLookup = new Set(itemList.map(({ id }) => id));

Directly from a Collection or Map instance is faster than e.g. by iterating over the array over and over again or contains external filtering tasks.

Filtering unmatched item-id List is as simple as...

const listOfNonMatchingIds = idList.filter(id => !idLookup.has(id));

...Example code...

const itemList = [
  { id: 60, itemName: 'Main Location - 1100 Superior Road - Cleveland' },
  { id: 1456, itemName: 'Third Location - 107,West 20th Street,Manhattan - New York' },
];
const idList = [60, 1453, 1456];

const idLookup = new Set(itemList.map(({ id }) => id));
const listOfNonMatchingIds = idList.filter(id => !idLookup.has(id));

console.log({ listOfNonMatchingIds });

.as-console-wrapper { min-height: 100%!important; top: 0; }

Answer 2

You can use .map() and then .filter() and .includes ()

const data = [
  {id: 60, itemName: 'Main Location - 1100 Superior Road - Cleveland'},
  {id: 1456, itemName: 'Third Location - 107,West 20th Street,Manhattan - New York'}
]

const ids = [60, 1453, 1456];
const dataIDs = data.map(ob => ob.id);  // [60, 1456]
const notExistentIDs = ids.filter(id => !dataIDs.includes(id));

console.log(notExistentIDs);  // [1453]