ECMAScript 2016+ Features

ES2016

1. Exponentiation (**)
2. Array.prototype.includes

ES2017

• Object.entries
• Object.values
• async/await
• JavaScript shared memory: SharedArrayBuffer, Atomics object
• padEnd, padStart (padding strings)
• trailing comma in function parameters

ES2018

• for-await-of (asynchronous iteration)
• Promise.prototype.finally
• object rest properties
• object spread
• RegExp features (s dotAll flag, named groups, negative look behind, Unicode)

ES2019

• Array.prototype.flat
• Array.prototype.flatMap
• Object.fromEntries

ES2020

• BigInt
• nullish coalescing operator
• optional chaining
• globalThis object

ES2021

• replaceAll
• Promise.any
• logical assignment operators (??=, &&=, ||=)
• WeakRef
• FinalizationRegistry
• separators for numeric literals (1_000)