Convert array of object with key value pair to a single object?

Question

I have an array of objects with key-value pair, how to convert it to an object by reducing it to a single object by removing keys. I tried with map filter reduce but couldn't get the desired result. please help

const object = Object.assign({}, ...obj); // not working
const result = {};

Object.keys(object).forEach((key, index) => {
    result[`newObj${index + 1}`] = obj[key].map(item => ({[key]: item}));
}); // not working

Input

   obj = [{key: name, value: jack},{key: age, value: 10},{key: country, value: india},{key: state, value: Delhi}];

Output

{name:jack, age:10, country:india, state: Delhi}

`obj` is not an object, it's an *array* of objects. If you loop over that array, each item of it will be an object with `.key` and `.value` properties, which you need to use somehow. `obj.forEach(i => result[i.key] = i.value)`… — deceze, Sep 23 '20 at 10:10
Pleas make your input valid, did you mean `{key:"name", ...}` instead of `{key:name,...}`? — Jan Stránský, Sep 23 '20 at 10:13
Nice how many different solutions there are there given in the answers — Jan Stránský, Sep 23 '20 at 10:32

Siva K V · Accepted Answer · 2020-09-23T10:28:08.103

3

Use forEach and destructuring

Update: Fixed based on Jan pointed out. Thanks @Jan

obj = [
  { key: "name", value: "jack" },
  { key: "age", value: 10 },
  { key: "country", value: "india" },
  { key: "state", value: "Delhi" },
];

const res = {};
obj.forEach(({ key, value }) => Object.assign(res, { [key]: value }));

console.log(res);

Alternatively, use Object.fromEntries and map

obj = [
  { key: "name", value: "jack" },
  { key: "age", value: 10 },
  { key: "country", value: "india" },
  { key: "state", value: "Delhi" },
];

const res = Object.fromEntries(obj.map(Object.values));

console.log(res);

edited Sep 23 '20 at 10:28

answered Sep 23 '20 at 10:17

Siva K V

10,561
2
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@JanStránský, You are right. I just updated. Thanks. – Siva K V Sep 23 '20 at 10:23
I would put the `Object.fromEntries(obj.map(Object.values))` solution as the first one and the `forEach` as an alternative :-) – Jan Stránský Sep 23 '20 at 10:30
@sivako this one line solution does the job.. thanks – Vishnu Shenoy Sep 23 '20 at 12:12

Zortext · Answer 2 · 2020-09-23T10:20:00.867

1

var obj=[{key: "name", value: "jack"},{key: "age", value: 10},{key: "country", value: "india"},{key: "state", value: "Delhi"}]
    
var myObj={};
for (var item of obj){
    myObj[item.key]=item.value
} 
console.log(myObj)

will output

{name: "jack", age: 10, country: "india", state: "Delhi"}

edited Sep 23 '20 at 10:20

answered Sep 23 '20 at 10:14

Zortext

566
8
21

Jan Stránský · Answer 3 · 2020-09-23T10:26:45.093

You can use reduce for this:

var input = [
    {key: "name", value: "jack"},
    {key: "age", value: 10},
    {key: "country", value: "India"},
    {key: "state", value: "Delhi"},
]
var output = input.reduce((r,{key,value}) => ({[key]:value,...r}),{})
console.log(output)

Output

{ state: 'Delhi', country: 'India', age: 10, name: 'jack' }

The solution uses

object destructuring {key,value}
object spread syntax {...r}
object computed property names {[key]:value}

score 0 · Answer 4 · answered Sep 23 '20 at 10:19

I think you want like this...

var obj = [
{key: "name", value: "jack"},
{key: "age", value: 10},
{key: "country", value: "india"},
{key: "state", value: "Delhi"}
];
let tempObject = {};

for (let c of obj) {
   tempObject[c.key]= c.value;
}

console.log(tempObject);

Convert array of object with key value pair to a single object?

4 Answers4