Ways to transform an Array into an object

Question

Ways to transform an Array into an object

I had the idea to create a personalized dictionary for customers by utilizing the reduce function. Currently, I am achieving this using the forEach method.

const customers = 
  [ { name: 'ZOHAIB', phoneNumber: '0300xxxxx', other: 'anything'     } 
  , { name: 'Zain',   phoneNumber: '0321xxxxx', other: 'other things' } 
  ] 

let customersDictionary = {};
customers.forEach(customer => {
  customersDictionary = {
      ...customersDictionary,
      [ customer.phoneNumber ]: {name: customer.name},
      };

However, my goal is to obtain the same result but with the reduce method.

customersDictionary = 
  { "0300xxxxx": {"name": "ZOHAIB"}
  , "0321xxxxx": {"name": "Zain"}
}

javascript dictionary

Answer 1

Answer №1

This code snippet is expected to provide the desired outcome.

let userList = [
  { username: "JohnDoe", email: "johndoe@example.com", role: "admin" },
  { username: "JaneSmith", email: "janesmith@example.com", role: "user" },
];

let userDictionary = userList.reduce(
  (acc, { email, username }) => ({
    ...acc,
    [email]: { username },
  }),
  {}
);

Answer 2

This code snippet is expected to provide the desired outcome.

let userList = [
  { username: "JohnDoe", email: "johndoe@example.com", role: "admin" },
  { username: "JaneSmith", email: "janesmith@example.com", role: "user" },
];

let userDictionary = userList.reduce(
  (acc, { email, username }) => ({
    ...acc,
    [email]: { username },
  }),
  {}
);

Answer 3

Answer №2

Forget about reduce. You can achieve the same result in just one line using a combination of Array.prototype.map and Object.fromEntries:

Object.fromEntries(customers.map(c => [c.phoneNumber, { name: c.name }]));

Alternatively, you could also use reduce like this:

customers.reduce((acc, c) => {
  acc[c.phoneNumber] = { name: c.name };
  return acc;
}, {});

Answer 4

Forget about reduce. You can achieve the same result in just one line using a combination of Array.prototype.map and Object.fromEntries:

Object.fromEntries(customers.map(c => [c.phoneNumber, { name: c.name }]));

Alternatively, you could also use reduce like this:

customers.reduce((acc, c) => {
  acc[c.phoneNumber] = { name: c.name };
  return acc;
}, {});

Ways to transform an Array into an object

Answer №1

Answer №2

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