Safe Deep Cloning with structuredClone

Snippet

Safe Deep Cloning with structuredClone

Unlike the JSON.parse(JSON.stringify()) hack, structuredClone creates a true deep copy that handles circular references and complex types like Date, Map, and Set.

snippet.js
javascript
const original = {
  user: 'Markus',
  roles: new Set(['admin', 'editor']),
  metadata: { created: new Date() }
};
 
const copy = structuredClone(original);
 
copy.roles.add('guest');
console.log(original.roles.has('guest')); // false
console.log(copy.metadata.created instanceof Date); // true

nodejs

Breakdown

structuredClone(original)

Performs a native deep clone of the entire object graph.

copy.roles.add('guest')

Modifying the copy does not affect the original Set.

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Safe Deep Cloning with structuredClone

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