28 lines
675 B
Markdown
28 lines
675 B
Markdown
---
|
|
title: isDeepFrozen
|
|
tags: object,recursion,intermediate
|
|
firstSeen: 2020-09-04T20:20:11+03:00
|
|
lastUpdated: 2020-10-20T23:02:01+03:00
|
|
---
|
|
|
|
Checks if an object is deeply frozen.
|
|
|
|
- Use recursion.
|
|
- Use `Object.isFrozen()` on the given object.
|
|
- Use `Object.keys()`, `Array.prototype.every()` to check that all keys are either deeply frozen objects or non-object values.
|
|
|
|
```js
|
|
const isDeepFrozen = obj =>
|
|
Object.isFrozen(obj) &&
|
|
Object.keys(obj).every(
|
|
prop => typeof obj[prop] !== 'object' || isDeepFrozen(obj[prop])
|
|
);
|
|
```
|
|
|
|
```js
|
|
const x = Object.freeze({ a: 1 });
|
|
const y = Object.freeze({ b: { c: 2 } });
|
|
isDeepFrozen(x); // true
|
|
isDeepFrozen(y); // false
|
|
```
|