Let and const
Widely available since 2019-03-20
The let and const declarations define block-scoped variables.
Learning resources on MDN
Browser support (view on caniuse.com)
- Chrome 49 Released on 2016-03-02
- Chrome Android 49 Released on 2016-03-09
- Edge 14 Released on 2016-08-02
- Firefox 44 Released on 2016-01-26
- Firefox for Android 44 Released on 2016-01-26
- Safari 10 Released on 2016-09-20
- Safari on iOS 10 Released on 2016-09-13
Specifications
- ECMAScript Language Specification (#sec-let-and-const-declarations), from TC39 (Ecma International).