Count Unicode code points in a string.
JavaScript: String iteration combines surrogate pairs, unlike the UTF-16 length property.
const text = "A😀";
console.log(text.length);
console.log([...text].length);Expected output EXAMPLE
3 2
Details
Save as snippet.js and run node snippet.js. Uses built-in Node.js and JavaScript APIs. String iteration combines surrogate pairs, unlike the UTF-16 length property.
Code points are not necessarily complete user-visible grapheme clusters.
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
14db175b891f6cf0c710b91a96fe1dd1c2c8bc7f85d79146b66f309354c81711- 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
3 2
Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.