Get specific value from object of arrays ES6 way

Question

I am having a data like

var d = [{
  "AD": {
    "name": "Andorra",
    "native": "Andorra",
    "phone": "376",
    "continent": "EU",
    "capital": "Andorra la Vella",
    "currency": "EUR",
  }
}, {
  "AE": {
    "name": "United Arab Emirates",
    "native": "دولة الإمارات العربية المتحدة",
    "phone": "971",
    "continent": "AS",
    "capital": "Abu Dhabi",
    "currency": "AED",
  }
}, {
  "AF": {
    "name": "Afghanistan",
    "native": "افغانستان",
    "phone": "93",
    "continent": "AS",
    "capital": "Kabul",
    "currency": "AFN",
  }
}]

and i want to get the name of each object using ES6 higher-order functions without using for or foreach.

i have tried filter and map but not knowing when to use what

Name of each object means `Andorra`, `United Arab Emirates` and `Afghanistan`? — Orelsanpls, Sep 21 '18 at 12:37
This is a horrible structure. Don't use different properties in objects in the same array. — Bergi, Sep 21 '18 at 12:44

score 0 · Answer 1 · answered Sep 21 '18 at 12:38

You can easily achieve that using Array.prototype.reduce() as follows:

var d = [{
  "AD": {
    "name": "Andorra",
    "native": "Andorra",
    "phone": "376",
    "continent": "EU",
    "capital": "Andorra la Vella",
    "currency": "EUR",
  }
}, {
  "AE": {
    "name": "United Arab Emirates",
    "native": "دولة الإمارات العربية المتحدة",
    "phone": "971",
    "continent": "AS",
    "capital": "Abu Dhabi",
    "currency": "AED",
  }
}, {
  "AF": {
    "name": "Afghanistan",
    "native": "افغانستان",
    "phone": "93",
    "continent": "AS",
    "capital": "Kabul",
    "currency": "AFN",
  }
}] 

const names = d.reduce((acc, curr) => {
  const keys = Object.keys(curr);
  const name = curr[keys[0]].name;
  acc.push(name)
  return acc;
}, []);

console.log(names)

Why using a `Array.reduce`, compared to an `Array.map`? – Orelsanpls Sep 21 '18 at 12:46 — Orelsanpls, Sep 21 '18 at 12:46

score -1 · Answer 2 · answered Sep 21 '18 at 12:38

The simply way to achieve that is for me :

var d = [{
  "AD": {
    "name": "Andorra",
    "native": "Andorra",
    "phone": "376",
    "continent": "EU",
    "capital": "Andorra la Vella",
    "currency": "EUR",
  }
}, {
  "AE": {
    "name": "United Arab Emirates",
    "native": "دولة الإمارات العربية المتحدة",
    "phone": "971",
    "continent": "AS",
    "capital": "Abu Dhabi",
    "currency": "AED",
  }
}, {
  "AF": {
    "name": "Afghanistan",
    "native": "افغانستان",
    "phone": "93",
    "continent": "AS",
    "capital": "Kabul",
    "currency": "AFN",
  }
}] 

d.map(item => {
 console.log(Object.keys(item));
})

Sorry that's not what the OP asked for – Orelsanpls Sep 21 '18 at 12:46 — Orelsanpls, Sep 21 '18 at 12:46

score -1 · Answer 3 · answered Sep 21 '18 at 12:40

If there are only one key per object (AD, AE, AF...) you can use something like :

const d = [{
  AD: {
    name: 'Andorra',
  }
}, {
  AE: {
    name: 'United Arab Emirates',
  }
}, {
  AF: {
    name: 'Afghanistan',
  },
}];

const reduced = d.map(x => x[Object.keys(x)[0]].name);

console.log(reduced);

If there can be multiple key like (AD, AE, ...) you can use something like :

const d = [{
  AD: {
    name: 'Andorra',
  },

  DF: {
    name: 'Paris',
  },
}, {
  AF: {
    name: 'Afghanistan',
  },
}];

const reduced = d.reduce((tmp, x) => [
  ...tmp,
  
  ...Object.values(x).map(y => y.name),
], []);

console.log(reduced);

Get specific value from object of arrays ES6 way

3 Answers3