Parameter expansion requires a bit of practice, but it can be very useful once you’ve become familiar with its many ...

The JavaScript method, Array.map(f) is a pure function in that it takes a function as a parameter. That last point about pure functions warrants further exploration. First-order functions vs. pure ...

Express is a popular HTTP server and middleware platform for Node.js, and here you'll learn some of the top reasons why. Get started with request handling and more in Express.js.

Those are examples of higher-order functions that accept functions as arguments, but plenty of them return functions as well. If you’ve ever seen a function call that has two sets of parentheses ...