Add a key to each value in json array javascript

Question

I would like to transform the below JSon. The input JSon array can be of any size. I know its a basic question but I can't find the duplicate.

 var input = [{
    "value": 1
 }, {
    "value": 2
 }]

 var output = [{
    "key": {
        "value": 1
    }
 }, {
    "key": {
        "value": 2
    }
 }]

Appreciate all the help.

what are you transforming this json array into? -

Denis Tsoi
– Denis Tsoi

2017-03-06 14:51:41 +00:00
Commented Mar 6, 2017 at 14:51 — Denis Tsoi
– Denis Tsoi, Commented Mar 6, 2017 at 14:51

kind user · Accepted Answer · 2017-03-06 14:51:17Z

3

Create a new array and use Array#forEach to push an object with key = key and a currently iterated object from input as the value.

var input = [{value:1},{value:2}],
    result = [];
    input.forEach(v => result.push({ 'key': v }));
    
    console.log(result);

answered Mar 6, 2017 at 14:51

kind user

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Comments

kvn · Accepted Answer · 2017-03-06 15:59:57Z

2

Try using this, this should solve your problem

output = input.map(value => ({ "key": value }) );
console.log(output);

I used ES6 for simplicity, but this does exactly the same.

edited Mar 6, 2017 at 15:59

answered Mar 6, 2017 at 14:51

kvn

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3 Comments

Nina Scholz Over a year ago

you could wrap the object in parens input.map(value => ({ "key": value }));

kvn Over a year ago

Right. Thanks :) Updated the answer now.

kvn Over a year ago

I agree. It is simpler and more complex at the same time, but that is a different discussion altogether.

Michał Sadowski · Accepted Answer · 2017-03-06 14:56:18Z

-1

I think this will be the most oldschool and hands-on way of doing this.

var input = [{
    "value": 1
 }, {
    "value": 2
 }],
 output = [],
 newItem,
 i = 0, ii = input.length;
 
 
 for(i; i<ii; i++){
  newItem = {};
  newItem.key = {"value":input[i].value};
  output.push(newItem);
 }
 
 console.log(output)

answered Mar 6, 2017 at 14:56

Michał Sadowski

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