Build Json from an array of objects

Question

I'm trying to use typescript to build a json object from an array of objects like this one:[

[
  { attribute: 'a', modifier: 121 },
  { attribute: 'b', modifier: 67 },
  { attribute: 'c', modifier: 121 },
  { attribute: 'd', modifier: 67 } 
]

I would like to get something like:

{
  a:  121,
  b:  67,
  c:  121,
  d:  67  
}

But I just can't get my head around the high order functions to make it work.

Glorfindel · Accepted Answer · 2023-04-05 08:01:52Z

5

You could use reduce method which accepts as parameter a callback function.

Read more about reduce method here.

let array=[
  { attribute: 'a', modifier: 121 },
  { attribute: 'b', modifier: 67 },
  { attribute: 'c', modifier: 121 },
  { attribute: 'd', modifier: 67 } 
];
let obj=array.reduce(function(obj,item){
  obj[item.attribute] = item.modifier;
  return obj;
},{});
console.log(obj);

edited Apr 5, 2023 at 8:01

Glorfindel

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answered Sep 21, 2017 at 11:08

Mihai Alexandru-Ionut

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Comments

Nina Scholz · Accepted Answer · 2017-09-21 11:15:03Z

2

You could use Object.assign in combination with Array#map.

var array = [{ attribute: 'a', modifier: 121 }, { attribute: 'b', modifier: 67 }, { attribute: 'c', modifier: 121 }, { attribute: 'd', modifier: 67 }],
    result = Object.assign(...array.map(o => ({ [o.attribute]: o.modifier })));

console.log(result);

With destructuring assignment

var array = [{ attribute: 'a', modifier: 121 }, { attribute: 'b', modifier: 67 }, { attribute: 'c', modifier: 121 }, { attribute: 'd', modifier: 67 }],
    result = Object.assign(...array.map(({ attribute, modifier }) => ({ [attribute]: modifier })));

console.log(result);

edited Sep 21, 2017 at 11:15

answered Sep 21, 2017 at 11:09

Nina Scholz

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Comments

gurvinder372 · Accepted Answer · 2017-09-21 11:10:36Z

1

try this.

var arr = [
  { attribute: 'a', modifier: 121 },
  { attribute: 'b', modifier: 67 },
  { attribute: 'c', modifier: 121 },
  { attribute: 'd', modifier: 67 } 
]
var map = {};
arr.forEach( function(item){ map[ item.attribute ] = item.modifier });
console.log( JSON.stringify( map, 0, 4 ) )

answered Sep 21, 2017 at 11:10

gurvinder372

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