Convert a simple Array to complex Object with items as child array

Question

Using javascript ES6, I'm trying without success to get an easy algorithm to convert an array who contains a string, no size limit and I need as a result an object with array items as label and every item in a child array, depending on his position, kind of hard to explain,

Here is what I got "before" and what I want "after".

before = ["a","b","c","d"]

after = {
        name: "a"
        children: [
            {
                name: "b",
                children: [
                    {
                        name: "c",
                        children: [
                            name: "d"
                        ]
                    }
                ]
            }
        ]
    }

I'm totally blocked thanks for any help

Are you open to using recursion?

Harvtronix
– Harvtronix

2017-12-20 19:17:07 +00:00
Commented Dec 20, 2017 at 19:17 — Harvtronix
– Harvtronix, Commented Dec 20, 2017 at 19:17
Yes i don't know so much about that actually ..

Peter
– Peter

2017-12-20 19:19:24 +00:00
Commented Dec 20, 2017 at 19:19 — Peter
– Peter, Commented Dec 20, 2017 at 19:19

Ori Drori · Accepted Answer · 2017-12-20 19:23:15Z

2

You can use Array#reduceRight to create the structure from the array.

The reduceRight() takes an element from the end, wraps it with the object, and add the previous result into the children array. The children are assign conditionally using Object#assign, since the last object doesn't have children.

const before = ["a","b","c","d"];

const after = before.reduceRight((r, name) => 
  Object.assign({ name }, r !== null ? { children: [r] } : {}), 
  null);

console.log(after);

edited Dec 20, 2017 at 19:23

answered Dec 20, 2017 at 19:19

Ori Drori

196k32 gold badges243 silver badges233 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Ben Aston · Accepted Answer · 2017-12-20 19:37:48Z

1

This is my solution:

const after = ([name, ...rest], children = rest.length && [after(rest)]) => 
  children 
    ? { name, children } 
    : { name };

const before = ['a', 'b', 'c', 'd'];
console.log(JSON.stringify(after(before), null, 2));

answered Dec 20, 2017 at 19:37

Ben Aston

56k69 gold badges221 silver badges351 bronze badges

Comments

Tao · Accepted Answer · 2017-12-20 19:40:08Z

1

This solution is similar to the one by Ori Dori, but it doesn't use Object#assign.

["a","b","c","d"].reduceRight((r, v, i) => {
    r.name = v;
    return i === 0 ? r : { children: [r] }
}, {});

answered Dec 20, 2017 at 19:40

Tao

2,25016 silver badges15 bronze badges

Comments

Anderson Pimentel · Accepted Answer · 2017-12-21 10:50:36Z

1

Another answer, without using those fancy const and reduceRight stuff! =D

var before = ["a","b","c","d"];

var after = createChildren(before);

console.log(after);

function createChildren(obj) {
    if (obj.length) {
      return { name: obj.shift(), children: [ createChildren(obj)] };
    }
    return new Array();
}

Shorter version:

var before = ["a","b","c","d"];

var after = createChildren(before);

console.log(after);

function createChildren(obj) {
    return obj.length && { name: obj.shift(), children: [ createChildren(obj)] } ||
           new Array();
}

edited Dec 21, 2017 at 10:50

answered Dec 20, 2017 at 19:29

Anderson Pimentel

5,8532 gold badges37 silver badges59 bronze badges

Collectives™ on Stack Overflow

Convert a simple Array to complex Object with items as child array

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related