In general, handling array functions like we’ve seen here, using JavaScript’s built-in functions like map() and filter(), is an excellent application of the power of functional programming.

Arrays can be slice d or splice d, but one of them will modify the original array in place and the other will return a new array. When you find cases like this, always prefer methods that return ...

First-order functions A first-order function takes standard data types (string, number, boolean, array, object) as parameters and returns any of these standard data types too. Also, a first-order ...