OB = {
"138": {
"img": "album_img_608842801.png",
"children": {
"215": {
"img": "album_img_386920978.png",
"children": {
"217": {
"name": "Veronica Zemanova",
"children": {
"218": {
"img": "album_img_884191953.png",
"children": {
"226": {
"img": "album_img_912163411.png",
"children": {
"229": {
"img": "album_img_221377469.png",
}
}
}
}
}
}
}
}
}
}
}
};
Python code I was able to make
def recursive_items(dictionary):
for key, value in dictionary.items():
if type(value) is dict:
yield (key, value)
yield from recursive_items(value)
else:
yield (key, value)
for key in recursive_items(OB):
print(key)
How can this code be rewritten for js? The size of the array is initially unknown We need to get the result in the form: [138,215,217,218,226,229] Thanks everyone for the replies!
Similar to your python solution, we will recursively traverse the object.
We test if the key is a number, and if it is, we yield it, and all of the number keys of its children.
function* defines a generator function in JavaScript.
yield yields a new value in the generator
yield* yields all the values in the iterable given. (Similar to yield from in Python, if I had to guess)
More info at https://javascript.info/generators
const OB = {
"138": {
"img": "album_img_608842801.png",
"children": {
"215": {
"img": "album_img_386920978.png",
"children": {
"217": {
"name": "Veronica Zemanova",
"children": {
"218": {
"img": "album_img_884191953.png",
"children": {
"226": {
"img": "album_img_912163411.png",
"children": {
"229": {
"img": "album_img_221377469.png",
}
}
}
}
}
}
}
}
}
}
}
};
// generator function, like python
function* numberKeys(obj) {
// for each key in the object
for (const key in obj) {
// if the key is a number
if (!isNaN(key)) {
// then we yield the key
yield key;
// then we yield all the number keys of the children
yield* numberKeys(obj[key].children);
}
}
}
for (const key of numberKeys(OB)) {
console.log(key);
}Here's another method that uses Object.keys to return an array of keys and Array.prototype.reduce to process it. It's a similar method to @kellys, but I don't use generators (perhaps I should) and thought I'd drop this here in case it's helpful.
function pluckNumericKeys(obj, acc = []) {
return Object.keys(obj).reduce((acc, key) => {
if (!isNaN(key)) acc.push(key)
if (typeof obj[key] === 'object') acc = pluckNumericKeys(obj[key], acc)
return acc
}, acc)
}
const OB = {
"138": {
"img": "album_img_608842801.png",
"children": {
"215": {
"img": "album_img_386920978.png",
"children": {
"217": {
"name": "Veronica Zemanova",
"children": {
"218": {
"img": "album_img_884191953.png",
"children": {
"226": {
"img": "album_img_912163411.png",
"children": {
"229": {
"img": "album_img_221377469.png",
}
}
}
}
}
}
}
}
}
}
}
}
const result = pluckNumericKeys(OB)
console.log(result)You can recursively get all the children key value using array#map and flatten the result.
const OB = { "138": { "img": "album_img_608842801.png", "children": { "215": { "img": "album_img_386920978.png", "children": { "217": { "name": "Veronica Zemanova", "children": { "218": { "img": "album_img_884191953.png", "children": { "226": { "img": "album_img_912163411.png", "children": { "229": { "img": "album_img_221377469.png", } } } } } } } } } } } };
const getKeys = o => Object.keys(o).map(k => ([k, o[k].children ? getKeys(o[k].children) : []])).flat(Infinity);
console.log(getKeys(OB));.as-console-wrapper { max-height: 100% !important; top: 0; }