How can I pass parameter correctly?

const root = {
    user: (id) => {
        console.log("returning object " + JSON.stringify(id.id) + " " + JSON.stringify(storage.select("users", id.id)))
        return storage.select("users", id.id)
    }
}

I want to call the arrow function in root.user but I think I can't pass the parameter correctly, so I tried this --> let user = root.user('101')
and on the console I got this -->

returning object undefined

[{"firstName":"Gokhan","lastName":"Coskun","login":"gcoskun","id":101}]
{"firstName":"George","lastName":"Clooney","login":"gclooney"}
[{"firstName":"Gokhan","lastName":"Coskun","login":"gcoskun","id":101}]

I wanted the user with the id 101 get returned and got instead all of the users returned.

Why are you doing id.id but passing a string? You either pass an object with an id prop (root.user({ id: '101' })) or replace id.id with simply id.

Also, it looks like the id fields in your user objects are of type number, while you are passing a string, so depending on the logic inside storage.select you might have to change that.

Passing a number id:

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

// Just mocking it for the example:
const storage = {
  select(key, id) {
    return [
      { firstName: 'Gokhan', lastName: 'Coskun', login: 'gcoskun', id: 101 },
      { firstName: 'George', lastName: 'Clooney', login: 'gclooney' }, 
      { firstName: 'Gokhan', lastName: 'Coskun', login: 'gcoskun', id: 101 },
      // Depending on the logic here, these types need to match.
      // Using == instead of === so that it's not required here.
    ].filter(user => user.id == id)
  },
};

const root = {
  user: (id) => {
      console.log(`ID = ${ id }`);
      
      // We make sure we only return a single user or null if there isn't one:
      return storage.select('users', id)[0] || null;
  },
};


const user = root.user('101');

console.log(user);

<!-- end snippet -->

Passing an object with an id prop of type number:

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

// Just mocking it for the example:
const storage = {
  select(key, id) {
    return [
      { firstName: 'Gokhan', lastName: 'Coskun', login: 'gcoskun', id: 101 },
      { firstName: 'George', lastName: 'Clooney', login: 'gclooney' }, 
      { firstName: 'Gokhan', lastName: 'Coskun', login: 'gcoskun', id: 101 },
      // Depending on the logic here, these types need to match.
      // Using == instead of === so that it's not required here.
    ].filter(user => user.id == id);
  },
};

const root = {
  user: (query) => {
      console.log(`ID = ${ query.id }`);
      
      // We make sure we only return a single user or null if there isn't one:
      return storage.select('users', query.id)[0] || null;
  },
};

const user = root.user({ id: '101' });

console.log(user);

<!-- end snippet -->