ES2015 concepts and syntax

Web developers must stay current with the latest JavaScript features that promote simpler and more readable code. With polyfills enabling code written in ES2015 JavaScript to be used in unsupported browsers, there is a strong incentive for developers to begin using the new features and syntax. You'll be asked to show that you understand and can write ES2015 JavaScript code using:

  • JavaScript promises with ES2015 syntax that create asynchronous functions and incorporate graceful error handling
  • Variables that can be used with block scope, function scope, and made immutable depending on context using let, var, and const
  • String literals that include string interpolation and multi-line strings
  • Arrow functions that create anonymous functions and use an unbounded this
  • Default function parameters that initialize default values for a function when no argument or undefined is provided
  • for...of loops that can iterate over any iterable object while running a custom function on each
  • Maps that allow for arbitrary key and value pairs that are iterable and include non-string keys
  • Sets that contain only unique, iterable elements where an array would degrade performance