structuredClone

3 snippets in JavaScript

JSJavaScript

Deep Cloning Arrays

syntax

structuredClone(value)

example

const original = [
  { name: "Ava", scores: [90, 85] },
  { name: "Leo", scores: [78, 92] },
];
const clone = structuredClone(original);
clone[0].scores.push(100);

console.log(original[0].scores); // [90, 85] (not affected)
console.log(clone[0].scores);    // [90, 85, 100]

Note structuredClone handles nested objects, arrays, Maps, Sets, Dates, RegExps, and more. Does NOT clone functions, DOM nodes, or prototypes.

Deep Cloning Objects

JS · Objects

syntax

structuredClone(obj)

example

const original = {
  user: { name: "Kai", tags: ["admin", "editor"] },
  updatedAt: new Date(),
};
const clone = structuredClone(original);
clone.user.tags.push("viewer");

console.log(original.user.tags); // ["admin", "editor"]

Note Handles circular references, Dates, Maps, Sets, ArrayBuffers, and more. Does NOT clone functions, Errors, or DOM nodes.

structuredClone()

JS · Modern Features

syntax

const clone = structuredClone(value);

example

const original = {
  name: "Ava",
  scores: [95, 88, 72],
  metadata: { joined: new Date("2024-01-15") },
};
const clone = structuredClone(original);
clone.scores.push(100);
clone.metadata.joined.setFullYear(2025);

console.log(original.scores);          // [95, 88, 72]
console.log(original.metadata.joined); // 2024-01-15 (unchanged)

Note Built-in deep clone that handles Dates, Maps, Sets, RegExps, ArrayBuffers, circular references. Cannot clone functions, DOM nodes, or Error objects.