I\'m developing an app and don\'t have to ever worry about Internet Explorer and was looking into some of the features present in A+ grade browsers that aren\'t in Inte
A great deal of time has passed since this question was first asked: the 'let' and 'const' keywords have been introduced in ECMAScript 2015 (ES6). Search for 'let' or 'const' in this awesome ES6 compatibility table:
https://kangax.github.io/compat-table/es6/