JS 2026
A yearly language edition collects specification changes, but support is implemented feature by feature. Check the exact API you intend to use.
Where to run this
This example uses the JavaScript console playground. Select Run to execute it; the example does not run on this lesson page.
A practical example
console.log("Temporal available:", typeof Temporal !== "undefined");
console.log("RegExp.escape available:", typeof RegExp.escape === "function");
What happens
The booleans describe this runtime rather than promising support based on its year.