New JavaScript features in ES2019:
Array#{flat,flatMap}
Object.fromEntries
String#{trimStart,trimEnd}
Symbol#description
try { } catch {} // optional binding
JSON ⊂ ECMAScript
well-formed JSON.stringify
stable Array#sort
revised Function#toString
BigInt is another example. This proposal provides a way to take care of it: https://github.com/gibson042/ecma262-proposal-JSON-parse-with-source … (Sadly, we cannot change JSON itself, meaning we cannot change JSON.stringify by default.)
JavaScript, HTML, CSS, HTTP, performance, security, Bash, Unicode, i18n, macOS.