JavaScript playground
Write JavaScript and run it instantly. Ideal for trying out an idea without opening your editor.
A place to try things out: iterate an array, see what a method returns, check an expression. The code runs isolated in your browser; it is not sent anywhere.
Editor
JavaScript actually runs
console
Use
console.log(...) to see values. The code runs in a sandbox with no access to this page; infinite loops are stopped after 4 seconds.Ideas to try
// ¿qué devuelve esto?
console.log(typeof null);
console.log(0.1 + 0.2);
console.log([1, 2, 3].map(x => x * x));
console.log("5" + 3, "5" - 3);
console.log([..."hola"]);
console.log(Object.entries({ a: 1, b: 2 }));When you want to learn a topic in depth: JavaScript examples · JavaScript cheat sheet · Python playground