I have an array of objects. I want to efficiently extract keys and its value out of it.

Example:

let data = [{'Car':'Honda'}, {'car':'Volvo'}];

I want car as key and its values separately. How I can achieve it in efficient manner (even using lodash)?

Expected output will be:

key : Car  value : Honda
key : car  value : Volvo

I have an array of objects. I want to efficiently extract keys and its value out of it.

Example:

let data = [{'Car':'Honda'}, {'car':'Volvo'}];

I want car as key and its values separately. How I can achieve it in efficient manner (even using lodash)?

Expected output will be:

key : Car  value : Honda
key : car  value : Volvo

• javascript
• typescript
• lodash

Share Improve this question Follow edited Oct 18, 2021 at 20:32 pride 8522 silver badges1111 bronze badges asked Jul 12, 2018 at 19:59 Deepender SharmaDeepender Sharma 49011 gold badge66 silver badges2626 bronze badges 3

• 5 What is expected output? keys and values in which format? in array, in bined object? – Zohaib Ijaz Commented Jul 12, 2018 at 20:01
• 2 What is your expected output? What have you tried so far? We can't help you if you don't show your work. – Soviut Commented Jul 12, 2018 at 20:01
• do you mean something like this? data.map(Object.entries); – Thomas Commented Jul 12, 2018 at 20:13

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4 Answers 4

Sorted by: Reset to default 4

You can iterate over the array and access the key and the value of properties for each object in question.

let data = [{
  'Car': 'Honda',
  'hello': 'hi'
}, {
  'car': 'Volvo'
}];

data.forEach((obj) => {
	Object.keys(obj).forEach((key) => {
  		console.log("key : " + key + " - value : " + obj[key]);
  });
});

lodash snippet

let data = [{
  'Car': 'Honda',
  'hello': 'hi'
}, {
  'car': 'Volvo'
}];

_.forEach(data, (obj) => {
	_.forEach(Object.keys(obj), (key) => {
  		console.log("key : " + key + " - value : " + obj[key]);
  });
});

<script src="https://cdnjs.cloudflare./ajax/libs/lodash.js/4.17.10/lodash.core.min.js"></script>

Object.entries https://developer.mozilla/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries

const newArray = data.map((item) => Object.entries(item));
// [[['Car', 'Honda']], [['car', 'Volvo']]]

You can use Object.entries(obj) to iterate over the keys and values.

data.forEach((obj) => 
Object.entries(obj).forEach(([key, value]) => 
console.log(key, value)));

let data = [{
  'Car': 'Honda',
  'hello': 'hi'
}, {
  'car': 'Volvo'
}];

data.forEach((obj) => 
Object.entries(obj).forEach(([key, value]) => 
console.log(key, value)));

Plain and simple way to do it would be:

var data = [{
  'Car': 'Honda'
}, {
  'Car': 'Volvo'
}];

var j = 0;
var carNames= [];
for (var i = 0; i < data.length; i++){
   var nameOfCar = data[i];
   if(nameOfCar.hasOwnProperty('Car')){
      carNames[j] = nameOfCar['Car'];
      j++;
   }
}


console.log(carNames);