Produce a lazy sequence with a generator.

TypeScript: A generator yields one value per iteration without building an intermediate array.

TypeScript snippet.ts
function* squares() {
  for (let value = 0; value < 4; value++) yield value * value;
}
console.log(JSON.stringify([...squares()]));

Expected output EXAMPLE

[0,1,4,9]

Details

Requires TypeScript and Node.js. Save as snippet.ts, compile with tsc --strict --target ES2022 --module commonjs snippet.ts, then run node snippet.js. A generator yields one value per iteration without building an intermediate array.

✓ Verified

Tested on Ubuntu 24.04.5 LTS · · TypeScript 5.9.3; Node.js v18.19.1 · bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3

Test inputs, results and environment

The exact published code ran in a dedicated Linux test container with prepared inputs. Snippet process uid 65534 with a read-only root filesystem and temporary working files. Networking disabled. 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 process) / C.UTF-8
Interpreter invocation
tsc --strict --target ES2022 --module commonjs snippet.ts && node snippet.js
Container image ID
sha256:ec91410a8f6ec3e985830b5e3a0560306d36f8c1c5ccd91a6699abe707123fa3
Code SHA-256
2df9ab3eb2beec2e5f0bebdf977abf3f54c9a8c96aa0e749d5c7d39a98981b7e
Dependencies
bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3

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

[0,1,4,9]

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