Swift · version 6

Run Swift 6 online

Swift 6 — run it in a Firecracker microVM on ls-judge. Real toolchain, no wrapper.

Starter code

What you get in Swift 6

Clicking "Run now" opens the playground with this exact code and a matching test case — passes on first Run.

swift
Swift 6
import Foundation
let line = readLine()!
let n = Int(line.trimmingCharacters(in: .whitespaces))!
print(n * 2)
stdin →21
expected →42
How it runs

How ls-judge runs Swift 6

Every submission is compiled and executed inside its own Firecracker microVM — the same isolation primitive AWS Lambda uses. No shared container, no shared kernel with other users' code. The Swift 6toolchain shipped with the microVM is the real thing (not a browser-side emulation): syscalls behave the way they do in production, and the compile / runtime behaviour matches what you would see on your own machine with that version installed.

Feed stdin from the Tests panel, watch verdicts stream per test case over a WebSocket. Free to use, no sign-up, works from any browser.

Other Swift versions
Swift 5all Swift →