67 lines
1.5 KiB
Markdown
67 lines
1.5 KiB
Markdown
---
|
|
title: Walk through object
|
|
tags: object,recursion,generator
|
|
author: chalarangelo
|
|
cover: bridge
|
|
firstSeen: 2020-12-31T13:03:15+02:00
|
|
lastUpdated: 2021-11-15T13:18:18+02:00
|
|
---
|
|
|
|
Creates a generator, that walks through all the keys of a given object.
|
|
|
|
- Use recursion.
|
|
- Define a generator function, `walk`, that takes an object and an array of keys.
|
|
- Use a `for...of` loop and `Object.keys()` to iterate over the keys of the object.
|
|
- Use `typeof` to check if each value in the given object is itself an object.
|
|
- If so, use the `yield*` expression to recursively delegate to the same generator function, `walk`, appending the current `key` to the array of keys. Otherwise, `yield` an array of keys representing the current path and the value of the given `key`.
|
|
- Use the `yield*` expression to delegate to the `walk` generator function.
|
|
|
|
```js
|
|
const walkThrough = function* (obj) {
|
|
const walk = function* (x, previous = []) {
|
|
for (let key of Object.keys(x)) {
|
|
if (typeof x[key] === 'object') yield* walk(x[key], [...previous, key]);
|
|
else yield [[...previous, key], x[key]];
|
|
}
|
|
};
|
|
yield* walk(obj);
|
|
};
|
|
```
|
|
|
|
```js
|
|
const obj = {
|
|
a: 10,
|
|
b: 20,
|
|
c: {
|
|
d: 10,
|
|
e: 20,
|
|
f: [30, 40]
|
|
},
|
|
g: [
|
|
{
|
|
h: 10,
|
|
i: 20
|
|
},
|
|
{
|
|
j: 30
|
|
},
|
|
40
|
|
]
|
|
};
|
|
[...walkThrough(obj)];
|
|
/*
|
|
[
|
|
[['a'], 10],
|
|
[['b'], 20],
|
|
[['c', 'd'], 10],
|
|
[['c', 'e'], 20],
|
|
[['c', 'f', '0'], 30],
|
|
[['c', 'f', '1'], 40],
|
|
[['g', '0', 'h'], 10],
|
|
[['g', '0', 'i'], 20],
|
|
[['g', '1', 'j'], 30],
|
|
[['g', '2'], 40]
|
|
]
|
|
*/
|
|
```
|