Functional Programming Is on the Rise

In imperative programming style, when faced with a problem of finding a sum of values in a list, we’d write something like this:
var sum = 0 // initial program state
for (x in list) { // loop over elements of list
sum += x // change program state
}However, we tend to write this kind of code less and less even in traditional programming languages. Truly mathematical functions like sin(x) still use a traditional maths notation in modern programming languages, but the dot notation of x.f() is becoming a standard for calling all other kinds of functions as more languages provide some form of extension functions² that decouple notation from the actual object-oriented programming with its methods. Types
Using and writing higher-order functions like filter becomes a norm, and so does support for functional types in statically typed programming languages.

Source: medium.com