📖 How to Use the JavaScript Runner
Type code in the editor. Supports all modern ES2024 syntax: arrow functions, async/await, destructuring, modules (except import), classes.
Click ▶ Run or press Ctrl+Enter. console.log, console.error, console.warn, and console.table output is captured and shown.
Green text = console.log. Red text = errors. Orange = warnings. Blue = info. Each log line shows its value type.
Use the example buttons (Hello World, Array ops, Async/Await, ES6 Class) to learn patterns and start with working code.
Instant Execution
Runs in your browser using the JavaScript engine already installed. No server round-trips.
Console Capture
All console.log, .error, .warn, .info, .table output captured and color-coded.
Error Messages
Runtime errors shown in red with line numbers where available.
Code Examples
Starter examples for common patterns: arrays, async, classes, DOM manipulation.