Functional programming languages are gaining significant traction in industry for building web applications. Functional programming languages coexist with existing procedural and logic language paradigms. To review programming language paradigms:
The allure of a functional or logic language is its expressiveness for developers and extensibility for multi-processor computing. Developers write few lines of code in functional and logic languages to express the same concept as in a procedural language, for example, selecting items from a list (above). Functional and declarative languages only specify the result to obtain, not the steps to obtain the result as in a procedural language. The compiler decides how to use multiple processors, threads, and computer servers to complete the computation.