How to convert array into nested objects in javascript

Question

I am trying to generate nested object from nested array using javascript. But so far not able to succeed.

Below is array example.

let arr = [
 '25',
 '25_29',
 '25_28',
 '25_28_35',
 '25_28_35_36',
 '20',
 '20_27',
 '20_26',
 '18',
 '18_48',
 '59',
 '34'
 ];

Below is object example.

let Obj = {
 25: {
 key: 25,
 child: {
 29: {
 key: 29, child: {}
 },
 28: {
 key: 28,
 child: {
 key: 35,
 child: {
 key: 36,
 child: {}
 }
 }
 }
 }
 },
 20: {
 key: 20,
 child: {
 27: {
 key: 27,
 child: {}
 },
 26: {
 key: 26,
 child: {}
 }
 }
 }
 }

Is there any possibility of doing same?

• junvar: I'm sure it's possible, though your input array is invalid, so you'll have to clarify if you want help.
• Mitesh Vanatwala: @junvar Array has been updated.

Answer 1

You could split the path and reduce the keys.

var array = ['25', '25_29', '25_28', '25_28_35', '25_28_35_36', '20', '20_27', '20_26', '18', '18_48', '59', '34'],
 result = array.reduce((r, s) => {
 s.split('_').reduce((o, key) => (o[key] = o[key] || { key, child: {} }).child, r);
 return r;
 }, {});
console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 2

let arr = ['25', '25_29', '25_28', '25_28_35', '25_28_35_36', '20', '20_27', '20_26', '18', '18_48', '59', '34'];
let obj = arr.reduce((obj, v) => {
 let keys = v.split('_');
 let o = obj;
 keys.forEach(key => {
 o[key] = o[key] || {key, child: {}};
 o = o[key].child;
 });
 return obj;
}, {});
console.log(obj);