CODEWITHSUNDEEP
javascriptarraysjavascript-objects
Jquino
Jquino

Reputation: 19

JavaScript objects property to array

I have the following object:

const movies = {
  1: {
    id: 1,
    name: 'Planet Earth',
  },
  2: {
    id: 2,
    name: 'Selma',
  },
  3: {
    id: 3,
    name: 'Million Dollar Baby',
  },
  4: {
    id: 4,
    name: 'Forrest Gump',
  },
  5: {
    id: 5,
    name: 'Get Out',
  },
};

Then I want an array with only the property id. To do so I've tried something like:

const moviesArray = Object.values(movies);
const idArray = moviesArray.map(movie => Object.values(movie)[0]);
console.log(idArray);

It prints idArray properly but my question is if am I missing a method to solve this problem.

Upvotes: 1

Views: 85

Answers (5)

The Spooniest
The Spooniest

Reputation: 2873

I this case, I'd be more inclined to use movie => movie.id as your mapper function, rather than movie => Object.values(movie)[0].

The issue with your current function is that it assumes id will always happen to be the first property in the Array returned by Object.values. That happens to be true with your current function as written, but I'm not sure you can necessarily guarantee that in the general case. Directly referencing movie.idworks even if the properties come in a different order. It should also be a bit faster, since you don't have to convert eaxh individual object to an Array each time.

Upvotes: 1

Shubham
Shubham

Reputation: 1793

May be you can go with more core version. In my solution the loop will be running only once.

const movies = {
  1: {
    id: 1,
    name: 'Planet Earth',
  },
  2: {
    id: 2,
    name: 'Selma',
  },
  3: {
    id: 3,
    name: 'Million Dollar Baby',
  },
  4: {
    id: 4,
    name: 'Forrest Gump',
  },
  5: {
    id: 5,
    name: 'Get Out',
  },
};


const idArray = [];
for (let i in movies) {
	idArray.push(movies[i].id);
}

console.log(idArray);

Upvotes: 0

Black Mamba
Black Mamba

Reputation: 15615

I think there wasn't a need for using Object.values in the map part here. It would have been same without it:

const movies = {
  1: {
    id: 1,
    name: 'Planet Earth',
  },
  2: {
    id: 2,
    name: 'Selma',
  },
  3: {
    id: 3,
    name: 'Million Dollar Baby',
  },
  4: {
    id: 4,
    name: 'Forrest Gump',
  },
  5: {
    id: 5,
    name: 'Get Out',
  },
};
const moviesArray = Object.values(movies);
    const idArray = moviesArray.map(movie => movie);
    console.log(moviesArray);

Upvotes: 0

Archita Panchal
Archita Panchal

Reputation: 7

const movies = {
  1: {
    id: 1,
    name: 'Planet Earth',
  },
  2: {
    id: 2,
    name: 'Selma',
  },
  3: {
    id: 3,
    name: 'Million Dollar Baby',
  },
  4: {
    id: 4,
    name: 'Forrest Gump',
  },
  5: {
    id: 5,
    name: 'Get Out',
  },
};

const moviesArray = Object.values(movies);
const idArray = moviesArray.map(movie => movie.id);
console.log(idArray);

Upvotes: 1

Nina Scholz
Nina Scholz

Reputation: 386868

You could use the id property directly:

const
    movies = { 1: { id: 1, name: 'Planet Earth' }, 2: { id: 2, name: 'Selma' }, 3: { id: 3, name: 'Million Dollar Baby' }, 4: { id: 4, name: 'Forrest Gump' }, 5: { id: 5, name: 'Get Out' } },
    moviesArray = Object.values(movies),
    idArray = moviesArray.map(movie => movie.id);

console.log(idArray);

Upvotes: 4

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