Copy nested structured data independently.

JavaScript: structuredClone creates an independent copy of supported structured values.

JavaScript snippet.js
const original = {tags: ["code"]};
const copy = structuredClone(original);
copy.tags.push("tips");
console.log(JSON.stringify(original));
console.log(JSON.stringify(copy));

Expected output EXAMPLE

{"tags":["code"]}
{"tags":["code","tips"]}

Details

Save as snippet.js and run node snippet.js. Uses built-in Node.js and JavaScript APIs. structuredClone creates an independent copy of supported structured values.

Keep in mind

Functions and some platform objects cannot be structured-cloned.

✓ Verified

Tested on Ubuntu 24.04.5 LTS · · v18.19.1 · nodejs 18.19.1+dfsg-6ubuntu5

Test inputs, results and environment

The exact published code ran in a dedicated Linux test container with prepared inputs. Unprivileged snippet process, external networking disabled, read-only root filesystem, and a fresh temporary working directory. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.

Architecture / host kernel
x86_64 / 6.18.54.1-microsoft-standard-WSL2
Snippet identity / locale
uid=65534, gid=65534 (unprivileged) / C.UTF-8
Interpreter invocation
node snippet.js
Container image ID
sha256:32dc2d998158b6554c99b73b533f423696a0f3e31e8cbea9db10b5eee9a2fadd
Code SHA-256
e0174b1ed001712cdfc5c823064bef44326711b0585dee47d53e5f30fe47bb19
Dependencies
nodejs 18.19.1+dfsg-6ubuntu5

Test input setup

These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.

# No input files required.

Observed standard output

{"tags":["code"]}
{"tags":["code","tips"]}

Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.