Comment by Ivan Bacher on "How to create nested child objects in Javascript from array?"

CommentHow to create nested child objects in Javascript from array?

Ivan Bacher

PhD candidate researching software visualisation

Nov 10, 2017

let list = ['a', 'b', 'c']

let root = {}
let parent = null;

for(let el of list) {

    if(parent === null)
        parent = nest(el, root)
    else {
        parent = nest(el, parent);
    }
}

function nest(el, parent) {
    let node = {}

    parent[el] = node;

    return node;
}

console.log(root);

Output

{ a: { b: { c: {} } } }

Veera Venkata Avinash

Be Awesome

Nov 10, 2017

how is this new node adding to recently created parent node

how will be root updated?

The function nest() takes two parameters 1) el and 2) parent.

The first time nest is called we pass a (first element of the array) and root to the function.

Nest() creates a new object called node. Node then gets added to the parent parameter. Parent corresponds to root the first time the function is called. Then node is returned.

A reference of node is actually returned and not a copy (THIS IS IMPORTANT). Therefore, when nest() gets called a second time the parent parameter is actually a reference to the first node object that was created in the previously called nest() function.

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