26 lines
599 B
Markdown
26 lines
599 B
Markdown
---
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title: isDeepFrozen
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tags: object,recursion,intermediate
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---
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Checks if an object is deeply frozen.
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- Use recursion.
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- Use `Object.isFrozen()` on the given object.
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- Use `Object.keys()`, `Array.prototype.every()` to check that all keys are either deeply frozen objects or non-object values.
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```js
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const isDeepFrozen = obj =>
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Object.isFrozen(obj) &&
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Object.keys(obj).every(
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prop => typeof obj[prop] !== 'object' || isDeepFrozen(obj[prop])
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);
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```
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```js
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const x = Object.freeze({ a: 1 });
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const y = Object.freeze({ b: { c: 2 } });
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isDeepFrozen(x); // true
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isDeepFrozen(y); // false
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```
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