[removed] Merge Two Arrays of Objects, Only If Not Duplicate (Based on Specified Object Key)

Question

Background

Say I have an initial array of objects:

var initialData = [
    {
        \'ID\': 1,
        \'FirstName\': \'Sally\'
    },
    {
              


        

Answer 1

I think the alternative solution proposed by @slider in the accepted answer, would be something like this:

const oldData = [
  { id: 1, name: 'John' },
  { id: 2, name: 'Jane' },
  { id: 3, name: 'Mike' },
];

const newData = [
  { id: 2, name: 'Jane' },
  { id: 4, name: 'Rick' },
  { id: 5, name: 'Jim' },
];

const usersMap = new Map();

oldData.forEach(user => usersMap.set(user.id, user));

newData.forEach(user => {
  const exists = usersMap.has(user.id);
  
  if (!exists) {
    usersMap.set(user.id, user);
  }
})

usersMap.forEach(user => console.log(user))