import { List } from 'linqts';

const arr = new List<number>([1, 2, 3, 4, 5])
  .Where(x => x > 3)
  .Select(y => y * 2)
  .ToArray(); // > [8, 10]

const query = people.Join(pets,
  person => person,
  pet => pet.Owner,
  (person, pet) =>
    ({ OwnerName: person.Name, Pet: pet.Name }));