Welcome to XCODX Online Compiler
Quick Start:
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Ctrl+L Clear output
Select a language and start coding.
Dart exists today for one dominant reason: Flutter, Google's UI toolkit that compiles a single codebase to iOS, Android, web, and desktop, powering apps from BMW, eBay Motors, and Google Pay. But the language stands on its own — Dart 3 brought sound null safety everywhere, records, and pattern matching, and the VM offers both JIT for fast iteration and AOT for production. Before logic gets buried inside a widget tree, it pays to prove it in plain Dart, and that's what this page is for: your program runs on the Dart VM with a live terminal, so stdin.readLineSync() pauses mid-run for your real input.
import 'dart:io';
void main() {
stdout.write('Enter your name: ');
final name = stdin.readLineSync() ?? 'friend';
stdout.write('How many squares should I compute? ');
final n = int.parse(stdin.readLineSync() ?? '0');
final squares = [for (var i = 1; i <= n; i++) i * i];
print('Hi $name! The first $n squares:');
print(squares.join(', '));
print('Their sum is ${squares.fold<int>(0, (a, b) => a + b)}.');
}Extract the model classes, parsing routines, and state logic from a Flutter feature and verify them as pure Dart before a single widget rebuild — a habit that saves hours of hot-reload guessing. Bootcamp and university students starting Flutter tracks can master the language layer (null safety, futures, collections, cascade notation) here first, and mobile-developer interview prep often includes plain-Dart algorithm rounds that map directly onto this stdin-driven format. Collection-if, spreads, and records all behave exactly as they will in your app.
Yes — the Dart VM process is attached to a live terminal, so readLineSync() blocks until you type a line and press Enter. Pair it with stdout.write for same-line prompts (print adds a newline), and you get the standard interactive console pattern shown in the example above.
No — Flutter needs its rendering engine and a device or emulator target, which a console sandbox doesn't provide. What runs here is command-line Dart on the VM, which is ideal for the non-UI majority of your code: models, validation, algorithms, async logic with Future and Stream.
Sound null safety is on — Dart 3 requires it — so nullable types must be handled explicitly, as the ?? defaults in the example show. Packages from pub.dev can't be fetched in the sandbox; you're working with the core libraries (dart:core, dart:io, dart:convert, dart:math, dart:async), which cover most practice needs.
main.dartdartstdin.readLineSync()void main() {
print('Hello from Dart!');
print('Welcome to XCODX Online Compiler!');
var message = 'Dart is awesome!';
print(message);
}