es2015

ES2015, officially ECMAScript 2015 and commonly known as ES6, is the sixth edition of the ECMAScript standard and the first major revision in many years. standardized by Ecma International under ECMA-262 and developed by the TC39 committee, it introduced a broad set of syntax and core library enhancements intended to modernize JavaScript for large-scale applications.

The edition added numerous features that changed everyday programming in JavaScript. Key additions include block-scoped variables with let and const, classes and class-related syntax, arrow functions, template literals, destructuring assignments, default parameters, and rest and spread operators. It also introduced modules with import and export syntax, enhanced object literals with computed property names, and support for iterators and the for...of loop. In addition, ES2015 standardized new collection types such as Map, Set, WeakMap, and WeakSet, the Symbol primitive, and Promises for asynchronous programming, along with generators using function*.

In terms of impact, ES2015 represented a significant shift in how JavaScript code is written and organized. Modules and class syntax encouraged modular, object-oriented programming, while new expressions and operators reduce boilerplate and improve readability. Because not all environments supported the features immediately, developers widely used transpilers like Babel and polyfills to backport ES2015 features to older browsers, leading to broader ecosystem tooling and compatibility guidance.

Since ES2015, the language has continued to evolve through an annual TC39 release cycle, with ES2016, ES2017, and later editions adding smaller, targeted improvements while maintaining backward compatibility.