Functional Programming Keywords

Think about Clojure, or maybe Scala (disclaimer: I don't know it).

So You Want to be a Functional Programmer

• Purity

  Pure Functions are very simple functions. They only operate on their input parameters.

• Immutability

  There are no variables in Functional Programming.

• Higher-Order Functions

  In Functional Programming, a function is a first-class citizen of the language. In other words, a function is just another value.

• Function Composition

  Code reuse sounds great but is difficult to achieve. Make the code too specific and you can’t reuse it. Make it too general and it can be too difficult to use in the first place.

• Currying

  A Curried Function is a function that only takes a single parameter at a time.

• Referential Transparency

  Referential Transparency is a fancy term to describe that a pure function can safely be replaced by its expression. An example will help illustrate this.

• Execution Order

  The order of execution in a Pure Functional Language can be determined by the compiler.

• Ramda, Map, Filter and Reduce

And the four items in bold are those I think the most important.